Toner, developer using the toner, image forming apparatus

ABSTRACT

A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.

TECHNICAL FIELD

The present invention relates to a toner, a developer using the tonerand an image forming apparatus.

BACKGROUND ART

Conventionally, a latent image formed electrically or magnetically in anapparatus such as electrophotographic image forming apparatus isvisualized by a toner for electrophotography (this may also be referredto simply as “toner”). For example, in electrophotography, anelectrostatic image (latent image) is formed on a photoconductor, thenthe latent image is developed with a toner, and a toner image is formed.The toner image is transferred on a transfer medium such as paper andthen fixed on the transfer medium such as paper. In a fixing step forfixing the toner image on transfer paper, a heat fixing method such asheat roller fixing method and heat belt fixing method is generally usedwidely for its energy efficiency.

In recent years, market increasingly demands a high-speed image formingapparatus and saving of energy, and a toner which has excellentlow-temperature fixing property and is able to provide a high-qualityimage is demanded. To obtain low-temperature fixing property of a toner,it is necessary for a binder resin of the toner to have a reducedsoftening temperature. However, when the binder resin has a lowsoftening temperature, so-called offset that a part of a toner imageadheres on a surface of a fixing member during fixing and transfers oncopy paper (hereinafter, also referred to as hot-offset) is likely tooccur. Also, heat-resistant storage stability of the toner decreases,and so-called blocking that toner particles fuse with one another undera high-temperature environment occurs. In addition, there are problemsof contamination that a toner fuses to an inside of a developing deviceor a carrier and a problem of toner filming on a surface of aphotoconductor.

As a technique to solve these problems, it has been known to use acrystalline resin as a binder resin of a toner. That is, the crystallineresin may soften rapidly at a melting point of the resin, and the tonermay have a reduced softening temperature close to the melting pointwhile ensuring heat-resistant storage stability at a temperature belowthe melting point. Thus, it is possible to support both low-temperaturefixing property and heat-resistant storage stability.

As a toner using a crystalline resin, toners using a crystalline resinas a binder resin that crystalline polyester is elongated bydiisocyanate have been proposed (see PTL1 and PTL2). These toners haveexcellent low-temperature fixing property but have insufficientheat-resistant storage stability, and they do not reach the qualityrequired in recent years.

Also, a toner using a crystalline resin having a crosslinking structureby an unsaturated bond containing a sulfonic acid group has beenproposed (see PTL3). This toner has improved heat-resistant storagestability compared to the prior art so far. Also, a technology of resinparticles having excellent low-temperature fixing property andheat-resistant storage stability by defining a ratio of a softeningtemperature to a heat of fusion peak temperature and viscoelasticproperties is disclosed (see PTL4).

CITATION LIST Patent Literature

-   PTL1 Japanese Patent Application Publication (JP-B) No. 04-024702-   PTL2 JP-B No. 04-024703-   PTL3 Japanese Patent (JP-B) No. 3910338-   PTL4 Japanese Patent Application Laid-Open (JP-A) 2010-077419

SUMMARY OF INVENTION Technical Problem

In studying low-temperature fixing of a toner, the present inventorsfound that a toner including a crystalline resin as a main component ofa binder resin was vulnerable to stirring stress in a developing device,resulting in image defects due to occurrence of toner or carrieragglomerate over time, since an increasing amount of the crystallineresin enhanced low-temperature fixing property but reduced hardness ofthe toner due to low resin hardness. In addition, it was found as aproblem as well that controlling a molecular weight or a melting pointof the crystalline resin as a means for low-temperature fixing was in atrade-off relationship with hot-offset resistance and heat-resistantstorage stability.

Also, a conventional toner including a crystalline resin as a binderresin may have difficulty in enabling fixing at a constant temperatureand a constant speed regardless of a type of paper. Thus, it isnecessary to control the fixing temperature or the process speed bydetecting the type of paper, resulting in increased complexity, size andcost of an image forming apparatus.

The present invention aims at solving the above problems in theconventional technologies and at achieving the following objection. Thatis, the present invention aims at providing a toner including acrystalline resin as a binder resin which is remarkably excellent inlow-temperature fixing property and is also excellent in heat-resistantstorage stability, stress resistance and transfer property. The presentinvention also aims at providing a toner including a crystalline resinas a binder resin which enables fixing at a constant temperature and aconstant speed regardless of a type of paper.

Solution to Problem

Means for solving the problems are as follows. That is:

The toner of the present invention is a toner including at least acrystalline resin as a binder resin, wherein a tetrahydrofuran solublecontent of the toner includes 5.0% or more as a peak area of a componenthaving a molecular weight of 100,000 or greater in a molecular weightdistribution measured by gel permeation chromatography (GPC), and thetetrahydrofuran soluble content of the toner has a weight-averagemolecular weight of 20,000 to 60,000.

Advantageous Effects of Invention

According to the present invention, it is possible to solve theaforementioned problems in the prior art and to provide a tonerincluding a crystalline resin as a binder resin which is remarkablyexcellent in low-temperature fixing property and is also excellent inheat-resistant storage stability, stress resistance and transferproperty and also to provide a toner which enables fixing at a constanttemperature and a constant speed regardless of a type of paper.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a diagram illustrating one example of a diffraction spectrumobtained by an x-ray diffraction measurement.

FIG. 1B is a diagram illustrating one example of a diffraction spectrumobtained by an x-ray diffraction measurement.

FIG. 2 is a diagram illustrating a ¹³C-NMR spectrum around a carbonylcarbon in polyurea.

FIG. 3 is a diagram illustrating an integrated molecular weightdistribution curve of a toner in Example 1.

FIG. 4 is a schematic explanatory diagram illustrating an example of animage forming apparatus of the present invention.

FIG. 5 is another schematic explanatory diagram illustrating an exampleof an image forming apparatus of the present invention.

FIG. 6 is a schematic explanatory diagram illustrating an example of atandem-type color image forming apparatus as an image forming apparatusof the present invention.

FIG. 7 is a partially enlarged schematic explanatory diagram of theimage forming apparatus of FIG. 6.

DESCRIPTION OF EMBODIMENTS

(Toner)

A toner of the present invention includes at least a crystalline resinas a binder resin, and it further includes a colorant, a releasing agentand other components according to necessity.

A tetrahydrofuran soluble content of the toner includes 5.0% or more asa peak area of a component having a molecular weight of 100,000 orgreater in a molecular weight distribution measured by gel permeationchromatography (GPC), and the tetrahydrofuran soluble content of thetoner has a weight-average molecular weight of 20,000 to 60,000.

As a result of intensive studies, the present inventors have found that,for a toner having a crystalline resin as a binder resin as a maincomponent, a property that viscoelasticity degrades rapidly above amelting point (sharp melt property), which had been conventionallyconsidered as effective for low-temperature fixing property, causes alarge variation in a fixing temperature range depending on a type ofpaper. Thus, the present inventors have found that fixing at a constanttemperature and a constant speed is possible regardless of a type ofpaper with a toner which includes more than a certain amount of a binderresin having a molecular weight greater than that used for aconventional toner with excellent low-temperature fixing property,specifically more than a certain amount of a component having amolecular weight converted to polystyrene standard measured by gelpermeation chromatography (GPC) of 100,000 or greater, and which has aweight-average molecular weight within a certain range.

Also, the present inventors have found that introduction of a urethanebond or a urea bond or both thereof in a crystalline resin increasescohesion derived from the bonds and that it is possible to improvehardness of the crystalline resin. The inventors have also found that itis possible to adjust degree of crystallization of the toner as a wholeby using two types of crystalline resins having a urethane bond or aurea bond or both thereof and that use of such two different crystallineresins can suppress degradation of heat-resistant storage stability ofthe toner (which is caused by introduction of a urethane bond or a ureabond or both thereof) as well as can improve hot-offset resistance ofthe toner.

A reason for the effect of the present invention is considered asfollows. A crystalline resin has a sharp melt property as describedabove, but internal cohesion and viscoelasticity of the toner in amolten state is highly dependent on a molecular weight and a structureof the resin. For example, when the resin includes a urethane bond or aurea bond as a bonding group having a large cohesive force, it behavessimilarly to a rubber-like elastic material at a relatively lowtemperature even during melting. However, because a thermal kineticenergy of the polymer chain increases as the temperature increases, thecohesion between the bonds loosens, and the resin gradually approaches aviscous body.

When such a resin is used as a binder resin for a toner, fixing may bepossible without a problem at a low fixing temperature. However, whenthe fixing temperature increases, a so-called hot-offset phenomenon thatan upper portion of a toner image adhere to a fixing member duringfixing due to small internal cohesive force during toner melting mayoccur, severely impairing image quality. When the urethane bond or theurea bond is increased to avoid hot-offset, fixing at a high temperaturemay be performed without problems. On the other hand, fixing at a lowtemperature results in low image gloss and insufficient meltimpregnation into paper, and the image is easily separated from thepaper. Especially when fixing on paper which is thick and has manyirregularities on a surface thereof, a fixing state deteriorates due tolow heat transfer efficiency of the toner during fixing. Also, for thetoner in an elastic state, the fixing state of the toner in a recesssignificantly deteriorates due to an insufficient pressure applied tothe toner in a fixing member.

When a molecular weight is considered as a means to controlviscoelasticity after melting, a larger molecular weight naturally has alarger viscoelasticity due to more obstacles to a movement of amolecular chain. Also, the molecular chain with a large molecular weighttangles, and as a result, it shows an elastic behavior. When a fixingproperty on paper is focused, a smaller molecular weight is preferablefor a smaller viscosity during melting, but hot offset occurs without acertain degree of elasticity. However, when the overall molecular weightis increased, fixing property is sacrificed, and the fixing stateespecially on thick paper deteriorates due to low heat transferefficiency. Thus, by incorporating a crystalline component having alarge molecular weight while the overall molecular weight of the binderresin is not increased too much, a toner which has a viscoelasticityafter melting favorably controlled and which may be fixed at a constanttemperature and a constant speed regardless of a type of paper such asthin paper and thick paper may be obtained.

<Binder Resin>

The binder resin includes at least a crystalline resin, and it furtherincludes an amorphous resin and other components according to necessity.

<<Crystalline Resin>>

The crystalline resin is not particularly restricted and may beappropriately selected according to purpose. It preferably includes acrystalline resin including a urethane bond or a urea bond or boththereof in a main chain thereof, and it more preferably includes acrystalline resin including a urethane bond or a urea bond or boththereof and a crystalline polyester unit.

The crystalline resin including a urethane bond or a urea bond or boththereof and a crystalline polyester unit preferably includes acrystalline resin including at least any one of a polyurethane unit anda polyurea unit, and a crystalline polyester unit, and it morepreferably includes a crystalline resin including a polyurethane unitand a crystalline polyester unit.

Also, the crystalline resin including a urethane bond or a urea bond orboth thereof preferably includes a component that a modified crystallineresin having an isocyanate group at an end thereof is elongated.

A crystalline resin in the present invention is a resin including aportion having a crystal structure, and it includes a diffraction peakderived from the crystal structure in a diffraction spectrum obtainedusing an x-ray diffractometer. The crystalline resin has a ratio of asoftening temperature measured using a capillary flow tester to amaximum peak temperature of heat of fusion measured using a differentialscanning calorimeter (DSC) (softening temperature/maximum peaktemperature of heat of fusion) of 0.8 to 1.6, indicating it has acharacteristic of softening sharply with heat.

Also, the binder resin may include a non-crystalline resin. Thenon-crystalline resin is a resin which does not include a crystallinestructure and has no diffraction peak derived from a crystallinestructure in a diffraction spectrum obtained using an x-raydiffractometer. The non-crystalline resin has a ratio of a softeningtemperature to a maximum peak temperature of heat of fusion (softeningtemperature/maximum peak temperature of heat of fusion) greater than1.6, indicating it has a characteristic of softening slowly with heat.

A softening temperature of a resin may be measured using a capillaryflow tester (for example, CFT-500 D (manufactured by ShimadzuCorporation)). While 1 g of a resin as a sample is heated at a heatingrate of 3° C./min, a load of 2.94 MPa is applied thereto using aplunger, and the sample is extruded from a nozzle having a diameter of0.5 mm and a length of 1 mm. An amount of descent of the plunger of theflow tester is plotted against the temperature, and a temperature atwhich half of the sample elutes off is regarded as a softeningtemperature.

The maximum peak temperature of heat of fusion of the resin may bemeasured using a differential scanning calorimeter (DSC) (for example, adifferential scanning calorimeter Q2000 (manufactured by TAInstruments)). As a pre-treatment, a sample for measuring the maximumpeak temperature of heat of fusion is melted at 130° C., cooled from130° C. to 70° C. at a rate of 10° C./min, and next cooled from 70° C.to 10° C. at a rate of 0.5° C./min. Here, an endothermic-exothermicchange is measured using a DSC by heating at a rate of 10° C./rain. The“endothermic-exothermic change” is plotted against the “temperature”,and an endothermic peak temperature observed at 20° C. to 100° C. isdefined as “Ta*”. When there are multiple endothermic peaks, atemperature having a peak with the largest endothermic quantity isdefined as Ta*. Thereafter, the sample is stored for 6 hours at atemperature of (Ta*−10° C. Next, the sample is cooled to 0° C. at acooling rate of 10° C./min and then heated at a heating rate of 10°C./min, and an endothermic-exothermic change is measured using a DSC. Asimilar plot is drawn, and a temperature corresponding to a maximum peakof an endothermic quantity is defined as a maximum peak temperature ofheat of fusion.

Regarding the endothermic quantity of a binder resin, the binder resinis heated from a room temperature to 150° C. at a heating rate of 10°C./min and left at 150° C. for 10 minutes, then it is cooled to a roomtemperature and left for 10 minutes, then it is heated again to 150° C.in a nitrogen atmosphere at a heating rate of 10° C./min, and a DSCmeasurement is performed. An area between the endothermic peak in thesecond temperature increase and the base line is defined as theendothermic quantity.

A content of the crystalline resin in the binder resin is notparticularly restricted and may be appropriately selected according topurpose. It is preferably 50% by mass or greater in view of fullydeveloping excellent low-temperature fixing property and heat-resistantstorage stability by the crystalline resin, and it is more preferably65% by mass or greater, further more preferably 80% by mass or greater,and particularly preferably 95% by mass or greater. When the content isless than 50% by mass, the binder resin cannot develop sharpresponsiveness to heat on the viscoelastic properties of the toner, andit is difficult to have both low-temperature fixing property andheat-resistant storage stability.

The maximum peak temperature of heat of fusion of the crystalline resinis not particularly restricted and may be appropriately selectedaccording to purpose. In view of having both low-temperature fixingproperty and heat-resistant storage stability, it is preferably 50° C.to 70° C., more preferably 55° C. to 68° C., and particularly preferably60° C. to 65° C. When the maximum peak temperature is less than 50° C.,low-temperature fixing property improves, but heat-resistant storagestability degrades. To the contrary, when it exceeds 70° C.,heat-resistant storage stability improves but the low-temperature fixingproperty degrades.

A ratio of the softening temperature to the maximum peak temperature ofheat of fusion is not particularly restricted as long as it is in arange of 0.8 to 1M, and it may be appropriately selected according topurpose. It is preferably 0.8 to 1.5, more preferably 0.8 to 1.4, andparticularly preferably 0.8 to 1.3. As the ratio decreases, the resinsoftens more sharply, which is superior in terms of having bothlow-temperature fixing property and heat-resistant storage stability.

The crystalline resin preferably includes a resin having a crystallinepolyester unit as a main component for easier design of melting pointfavorable as a toner and for excellent binding property to paper. Acontent of the resin having a crystalline polyester unit with respect tothe binder resin is preferably 50% by mass or greater, and morepreferably 60% by mass or greater, and further more preferably 75% bymass or greater, and particularly preferably 90% by mass or greater.This is because the toner has more superior low-temperature fixingproperty as the content of the resin having a crystalline polyester unitincreases.

Examples of the resin having a crystalline polyester unit include: aresin consisting of a crystalline polyester unit (also referred to assimply a crystalline polyester resin); a resin to which a crystallinepolyester unit is connected; and a resin to which a crystallinepolyester unit and other polymer units are connected (so-called blockpolymer or graft polymer).

Examples of the other polymer units include a non-crystalline polyesterunit, a polyurethane unit, a polyurea unit and a vinyl polymer unit.

The resin consisting of a crystalline polyester unit includes acrystalline structure at a large portion thereof, but it may be easilydeformed by an external force. A reason may be as follows. It isdifficult to crystallize all the portions of the crystalline polyester,and a molecular chain of a portion which is not crystallized(non-crystallized portion) has a high degree of freedom and easilydeforms. Regarding a portion having a crystalline structure, whichusually has a so-called lamellar structure as a higher-order structurethat layers formed by folded molecular chains are laminated, lamellarlayers are easily shifted because a large binding force between lamellarlayers does not work. When a binder resin for a toner is easilydeformed, problems may occur such as aggregation deformation in theimage forming apparatus, adhesion or fixing to a member and scratchescaused easily on a final image. Thus, the binder resin must havetoughness to withstand deformation to some extent with respect to anexternal force.

Thus, among the resins having a crystalline polyester unit, a resinwhere the crystalline polyester unit are linked together and a resinwhere the crystalline polyester unit is linked with other polymer units(so-called block polymer and graft polymer) each of the resinscontaining at least any one of a urethane bond, a urea bond and aphenylene bonding having large aggregation energy are preferable in viewof providing toughness to the resin.

It is considered that the urethane bond and the urea bond existing in amolecular chain may form pseudo-crosslinking points by means of largeintermolecular forces at non-crystalline portions or between lamellarlayers, and moreover they are wettable with respect to paper afterfixing thereon and enhance fixing strength. Thus, a resin with acrystalline polyester unit connected thereto, having a urethane bond ora urea bond or both thereof, and a resin with a crystalline polyesterunit and other polymer unit connected thereto, having a urethane bond ora urea bond or both thereof, are particularly preferable.

—Crystalline Polyester Unit—

Examples of the polyester unit include a polycondensation polyester unitsynthesized from a polyol and a polycarboxylic acid, a lactonering-opening polymerization product and a polyhydroxycarboxylic acid.Among these, a polycondensation polyester unit of a diol and adicarboxylic acid is preferable in terms of developing crystallinity.

—Polyol—

Examples of the polyol include a diol and a polyol having 3 to 8valences or more.

The diol is not particularly restricted and may be appropriatelyselected according to purpose. Examples thereof include: an aliphaticdiol such as straight-chain aliphatic diol and branched aliphatic diolhaving 2 to 36 carbon atoms in the chain; alkylene ether glycol having 4to 36 carbon atoms; an alicyclic diol having 4 to 36 carbon atoms; analkylene oxide (hereinafter abbreviated as AO) adduct of the alicyclicdiol; an AO adduct of bisphenols; a polylactone diol; a polybutadienediol; a diol having a carboxyl group and a diol having a sulfonic acidgroup or a sulfamic acid group; and a diol having other functionalgroups such as neutralized salt group. Among these, the aliphatic diolhaving 2 to 36 carbon atoms in the chain is preferable, and astraight-chain aliphatic diol is more preferable. These may be usedalone or in combination of two or more.

A content of the straight-chain aliphatic diol with respect to the diolas a whole is preferably 80% by mole or greater, and more preferably 90%by mole or greater. The content of 80% by mole or greater is preferablein terms of improved crystallinity of the resin, compatibility oflow-temperature fixing property and heat-resistant storage stability,and improved resin hardness.

The straight-chain aliphatic diol is not particularly restricted and maybe appropriately selected according to purpose. Examples thereof includeethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol,1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1-9-nonanediol,1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol,1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol and1,20-eicosanediol. Among these, ethylene glycol, 1,3-propanediol,1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol and 1,10-decanediol arepreferable in view of easy availability.

The branched aliphatic diol having 2 to 36 carbon atoms in the chain isnot particularly restricted and may be appropriately selected accordingto purpose. Examples thereof include 1,2-propyleneglycol, butanediol,hexanediol, octanediol, decanediol, dodecanediol, tetradecanediol,neopentyl glycol and 2,2-diethyl-1,3-propanediol.

The alkylene ether glycol having 4 to 36 carbon atoms is notparticularly restricted and may be appropriately selected according topurpose. Examples thereof include diethylene glycol, triethylene glycol,dipropylene glycol, polyethylene glycol, polypropylene glycol andpolytetramethylene ether glycol.

The alicyclic diol having 4 to 36 carbon atoms is not particularlyrestricted and may be appropriately selected according to purpose.Examples thereof include 1,4-cyclohexanedimethanol and hydrogenatedbisphenol A.

The AO adduct of the alicyclic diol is not particularly restricted andmay be appropriately selected according to purpose. Examples thereofinclude adducts (with addition of 1 to 30 moles) of ethylene oxide(hereinafter abbreviated as EO), propylene oxide (hereinafterabbreviated as PO) and buthylene oxide (hereinafter abbreviated as BO).

The bisphenols are not particularly restricted and may be appropriatelyselected according to purpose. Examples thereof include an AO (such asEU, PO and BO) adduct (with addition of 2 moles to 30 moles) ofbisphenol A, bisphenol F or bisphenol S.

The polylactone diol is not particularly restricted and may beappropriately selected according to purpose. Examples thereof includepoly-ε-caprolactone diol.

The diol having a carboxyl group is not particularly restricted and maybe appropriately selected according to purpose. Examples thereof includean dialkylol alkanoic acid having 6 to 24 carbon atoms such as2,2-dimethylol propionic acid (DMPA), 2,2-dimethylol butanoic acid,2,2-dimethylol heptanoic acid and 2,2-dimethylol octanoic acid.

The diol having a sulfonic acid group or a sulfamic acid group is notparticularly restricted and may be appropriately selected according topurpose. Examples thereof include: a sulfamic acid diol such asN,N-bis(2-hydroxyethyl)sulfamic acid and 2-mole PO adduct ofN,N-bis(2-hydroxyethyl) sulfamic acid; [N,N-bis(2-hydroxyalkyl)sulfamicacid (the alkyl group having 1 to 6 carbon atoms) and an AO adductthereof (AO is EO or PO, with addition of 1 to 6 moles); andbis(2-hydroxyethyl)phosphate.

The neutralized salt group of the diol having the neutralized salt groupis not particularly restricted and may be appropriately selectedaccording to purpose. Examples thereof include a tertiary amine having 3to 30 carbon atoms (e.g. triethylamine) and alkali metal (e.g. sodiumsalt).

Among these diols, an alkylene glycol having 2 to 12 carbon atoms, adiol having a carboxyl group, an AO adduct of bisphenols and acombination thereof are preferable.

The polyol having 3 to 8 valences or more used according to necessity isnot particularly restricted and may be appropriately selected accordingto purpose. Examples thereof include: a polyhydric aliphatic alcoholhaving 3 to 8 valences or more having 3 to 36 carbon atoms such asalkane polyol and an intramolecular or intermolecular dehydrationproduct thereof (e.g. glycerin, trimethylol ethane, trimethylol propane,pentaerythritol, sorbitol, sorbitan and polyglycerin), and a sugar and aderivative thereof (e.g. sucrose and methyl glucoside) an AO adduct(with addition of 2 to 30 moles) of trisphenols (e.g. trisphenol PA); anAO adduct (with addition of 2 to 30 moles) of a novolak resin (e.g.phenol novolak and cresol novolak); and an acrylic polyol such ascopolymer of a hydroxyethyl (meth)acrylate and other vinyl monomer.Among these, a polyhydric aliphatic alcohol having 3 to 8 valences ormore and an AO adduct of a novolak resin are favorable, and the AOadduct of a novolak resin is more favorable.

—Polycarboxylic Acid—

Examples of the polycarboxylic acid include dicarboxylic acid and apolycarboxylic acid having 3 to 6 valences or more.

The dicarboxylic acid is not particularly restricted and may beappropriately selected according to purpose. Favorable examples thereofinclude: an aliphatic dicarboxylic acid such as straight-chain aliphaticdicarboxylic acid and branched-chain aliphatic dicarboxylic acid; and anaromatic dicarboxylic acid. These may be used alone or in combination oftwo or more. Among these, a straight-chain aliphatic dicarboxylic acidis more preferable.

The aliphatic dicarboxylic acid is not particularly restricted and maybe appropriately selected according to purpose. Favorable examplesthereof include: an alkanedicarboxylic acid having 4 to 36 carbon atomssuch as succinic acid, adipic acid, sebacic acid, azelaic acid,dodecanedicarboxylic acid, octadecanedicarboxylic acid and decylsuccinicacid; an alkenedicarboxylic acids having 4 to 36 carbon atoms such asalkenylsuccinic acid including dodecenylsuccinic acid,pentadecenylsuccinic acid and octadecenylsuccinic acid, maleic acid,fumaric acid and citraconic acid; and cycloaliphatic dicarboxylic acidshaving 6 to 40 carbon atoms such as dimer acid (dimeric linoleic acid).

The aromatic dicarboxylic acid is not particularly restricted and may beappropriately selected according to purpose. Favorable examples thereofinclude an aromatic dicarboxylic acid having 8 to 36 carbon atoms suchas phthalic acid, isophthalic acid, terephthalic acid,t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid and4,4′-biphenyldicarboxylic acid.

Also, examples of the polycarboxylic acid having 3 to 6 valences or moreused according to necessity include an aromatic polycarboxylic acidhaving 9 to 20 carbon atoms such as trimellitic acid and pyromelliticacid.

Here, as the dicarboxylic acid or the polycarboxylic acid having 3 to 6valences or more, an acid anhydride or an lower alkyl ester having 1 to4 carbon atoms (e.g. methyl ester, ethyl ester and isopropyl ester) ofthose described above may also be used.

Among the dicarboxylic acid, the aliphatic dicarboxylic acid (preferablyadipic acid, sebacic acid or dodecanedicarboxylic acid) alone ispreferable. Similarly, it is preferable that the aliphatic dicarboxylicacid and the aromatic dicarboxylic acid (preferably terephthalic acid,isophthalic acid, t-butylisophthalic acid; and lower alkyl esters ofthese aromatic dicarboxylic acids) are coplymerized. An amount ofcopolymerization of the aromatic dicarboxylic acid is preferably 20% bymole or less.

—Lactone Ring-Opening Polymerization Product—

The lactone ring-opening polymerization product is not particularlyrestricted and may be appropriately selected according to purpose.Examples thereof include a lactone ring-opening polymerization productobtained by ring-opening polymerization of lactones including amono-lactone having 3 to 12 carbon atoms (having 1 ester group in thering) such as β-propiolactone, γ-butyrolactone, δ-valerolactone andε-caprolactone using a catalyst such as metal oxide and organometalliccompound, and a lactone ring-opening polymerization product having ahydroxyl group at an end thereof obtained by ring-opening polymerizationof the mono-lactones having 3 to 12 carbon atoms using a glycol (e.g.ethylene glycol and diethylene glycol) as an initiator. These may beused alone or in combination of two or more.

The mono-lactone having 3 to 12 carbon atoms is not particularlyrestricted and may be appropriately selected according to purpose. It ispreferably ε-caprolactone in view of crystallinity.

Also, a commercially available product may be used as the lactonering-opening polymerization product. Examples of the commerciallyavailable product include a highly crystalline polycaprolactone such asH1P, H4, H5 and H7 of PLACCEL series manufactured by Daicel Co., Ltd.

—Polyhydroxy Carboxylic Acid—

A method for preparing the polyhydroxy carboxylic acid is notparticularly restricted and may be appropriately selected according topurpose. Examples thereof include: a method of direct dehydrationcondensation of hydroxycarboxylic acids such as glycolic acid and lacticacid (e.g. L-form, D-form and racemic form); and a method ofring-opening polymerization of a cyclic ester having 4 to 12 carbonatoms (having 2 to 3 ester groups in the ring) corresponding to adehydration condensation product between 2 or 3 molecules ofhydroxycarboxylic acid such as glycolide and lactide (e.g. L-form,D-form and racemic form) using a catalyst such as metal oxide andorganometallic compound. Among these, the method of ring-openingpolymerization is preferable in view of molecular weight adjustment.

Among the cyclic esters, L-lactide and D-lactide are preferable in viewof crystallinity. Also, these polyhydroxy carboxylic acids may be thosewith their ends modified by a hydroxyl group or a carboxyl group.

<<Resin to which Crystalline Polyester Unit is Connected>>

As a method for obtaining the resin to which a crystalline polyesterunit is connected, for example, a crystalline polyester unit having anactive hydrogen group such as hydroxyl group at an end thereof isprepared beforehand, which is connected by a polyisocyanate. By usingthis method, it is possible to introduce a urethane bond in the resinskeleton, which may enhance toughness of the resin.

Examples of the polyisocyanate include diisocyanate and polyisocyanatehaving 3 or more valences.

The diisocyanate is not particularly restricted and may be appropriatelyselected according to purpose. Examples thereof include aromaticdiisocyanates, aliphatic diisocyanates, cycloaliphatic diisocyanates andaromatic aliphatic diisocyanates. These may be used alone or incombination of two or more.

Also, an isocyanate having three or more valences may be used incombination according to necessity.

The aromatic diisocyanates are not particularly restricted and may beappropriately selected according to purpose. Examples thereof include1,3- and/or 1,4-phenylene diisocyanate, 2,4- and/or 2,6-tolylenediisocyanate (TDI), crude TDI, 2,4′- and/or 4,4′-diphenylmethanediisocyanate (MDI), crude MDI [phosgene compound of crudediaminophenylmethane [condensation product of formaldehyde and aromaticamine (aniline) or a mixture thereof; mixture of diaminodiphenylmethaneand a small amount (5-20% by mass, for example) of a polyamine havingthree or more functional groups] polyallyl polyisocyanate (PAPI)],1,5-naphthylene diisocyanate, 4,4′,4″-triphenylmethane diisocyanate, andm- and p-isocyanatophenyl sulfonyl isocyanate.

The aliphatic diisocyanates are not particularly restricted and may beappropriately selected according to purpose. Examples thereof includeethylene diisocyanate, tetramethylene diisocyanate, hexamethylenediisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecenetriisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysinediisocyanate, 2,6-diisocyanato methylcaproate,bis(2-isocyanatoethyl)fumarate, bis(2-isocyanatoethyl)carbonate and2-isocyanatoethyl-2,6-diisocyanato hexanoate.

The alicyclic diisocyanates are not particularly restricted and may beappropriately selected according to purpose. Examples thereof includeisophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate(hydrogenated MDI), cyclohexylene diisocyanate, methyl cyclohexylenediisocyanate (hydrogenated TDI),bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, and 2,5- and2,6-norbornane diisocyanate.

The aromatic aliphatic diisocyanates are not particularly restricted andmay be appropriately selected according to purpose. Examples thereofinclude m- and p-xylylene diisocyanate (XDI) andα,α,α′,α″-tetramethylxylylene diisocyanate (TMXDI).

A modified product of the above diisocyanates is not particularlyrestricted and may be appropriately selected according to purpose.Examples thereof include a modified product including a urethane group,a carbodiimide group, an allophanate group, a urea group, a biuretgroup, an uretdione group, an uretoimin group, an isocyanurate group oran oxazolidone group. Specific examples thereof include; a modifieddiisocyanate including modified MDI such as urethane-modified MDI,carbodiimide-modified MDI, trihydrocarbyl phosphate-modified MDI, andurethane-modified TDI such as prepolymer including isocyanate; a mixtureof two or more types of these modified diisocyanates (e.g. a combinationof a modified MDI and a urethane-modified TDI).

Among these diisocyanates, those preferable include; an aromaticdiisocyanate having 6 to 20 carbon atoms, an aliphatic diisocyanatehaving 2 to 18 carbon atoms, an alicyclic diisocyanate having 4 to 15carbon atoms, an aromatic aliphatic diisocyanate having 8 to 15 carbonatoms, where the number of carbon atoms excludes the carbon in the NCOgroup; a modified product of these diisocyanates (e.g. a urethane group,a carbodiimide group, an allophanate group, a urea group, a biuretgroup, an uretdione group, an uretoimin group, an isocyanurate group oran oxazolidone group); and a mixture of two or more types thereof. Anaromatic diisocyanate having 6 to 15 carbon atoms, an aliphaticdiisocyanate having 4 to 12 carbon atoms and an alicyclic diisocyanatehaving 4 to 15 carbon atoms, where the number of carbon atoms excludesthe carbon in the NCO group, are more preferable, and TDI, MDI, HDI,hydrogenated MDI and IPDI are particularly preferable.

<<<Resin in which Crystalline Polyester Unit and Other Polymer Units areConnected>>>

A method for obtaining the resin to which a crystalline polyester unitand other polymer units are connected is not particularly restricted andmay be appropriately selected according to purpose. Examples thereofinclude: (1) preparing the crystalline polyester resin and the otherpolymer units separately beforehand and combining them; (2) preparing atleast any one of the crystalline polyester unit and the other polymerunits beforehand, and in the presence of the prepared unit, combining bypolymerizing the other polymer; and (3) polymerizing simultaneously orsequentially the crystalline polyester unit and the other polymer unitsin the same reaction field. In view of easily controlling the reactionas design intent, a favorable example of the method (1) and a favorableexample of the method (2) described below are preferable.

As the favorable example of the method (1), similarly to the method forobtaining the resin to which a crystalline polyester unit is connected,two or more types of units (i.e. crystalline polyester unit and otherpolymer units) having an active hydrogen group such as hydroxyl group atan end thereof are prepared beforehand, and These are combined withpolyisocyanate. As for the polyisocyanate, those described above may beused. Also, a method including introducing an isocyanate group at an endof one unit and reacting it with an active hydrogen group of the otherunit may be favorably used. It is possible to introduce a urethane bondin the resin skeleton using these methods, and accordingly toughness ofthe resin may be enhanced.

As a favorable example of the method (2), when the crystalline polyesterunit is prepared first and the polymer unit prepared next is anon-crystalline polyester unit, a polyurethane unit or a polyurea unit,a hydroxyl group or a carboxyl group at an end of the crystallinepolyester unit is reacted with a monomer for obtaining the other polymerunits. With this method, a resin in which the crystalline polyester unitand the other polymer units are connected may be obtained.

—Non-Crystalline Polyester Unit—

Examples of the non-crystalline polyester unit include apolycondensation polyester unit synthesized from a polyol and apolycarboxylic acid. As for the polyol and the polycarboxylic acid,those exemplified for the crystalline polyester unit may be used.However, in order for the unit to have no crystallinity, the polymerskeleton is designed to have many bending points and branching points.In order to provide the bending points, for example, AO (e.g. EO, PO andBO) adducts (with addition of 2 to 30 moles) of bisphenols such asbisphenol A, bisphenol F and bisphenol S and derivatives thereof may beused as the polyol, and phthalic acid, isophthalic acid ort-butylisophthalic acid may be used as the polycarboxylic acid. In orderto provide the branching points, the polyols and the polycarboxylicacids having 3 or more valences may be used.

—Polyurethane Unit—

Examples of the polyurethane unit include a polyurethane unitsynthesized from a polyol such as diol and polyol having 3 to 8 valencesor more and a polyisocyanate such as polyisocyanate having 3 or morevalences. Among these, the polyurethane unit synthesized from the dioland the diisocyanate is preferable.

Examples of the diol and the polyol having 3 to 8 valences or moreinclude those similar to the diol and the polyol having 3 to 8 valencesor more exemplified for the polyester resin.

Examples of the diisocyanate and the polyisocyanate having 3 or morevalences include those similar to the diisocyanate and thepolyisocyanate having 3 or more valences described above.

—Polyurea Unit—

Examples of the polyurea unit include a polyurea unit synthesized from apolyamine such as diamine and polyamine having 3 or more valences and apolyisocyanate such as diisocyanate and polyisocyanate having 3 or morevalences.

The diamine is not particularly restricted and may be appropriatelyselected according to purpose. Examples thereof include aliphaticdiamines and aromatic diamines. Among these, aliphatic diamines having 2to 18 carbon atoms and aromatic diamines having 6 to 20 carbon atoms arepreferable. Also, the amines having 3 or more valences may be usedaccording to necessity.

The aliphatic diamines having 2 to 18 carbon atoms are not particularlyrestricted and may be appropriately selected according to purpose.Examples thereof include: an alkylenediamine having 2 to 6 carbon atomssuch as ethylenediamine, propylenediamine, trimethylenediamine,tetramethylenediamine and hexamethylenediamine; a polyalkylenediaminehaving 4 to 18 carbon atoms such as diethylenetriamine,iminobispropylamine, bis(hexamethylene)triamine, triethylenetetramine,tetraethylenepentamine and pentaethylenehexamine; a hydroxyalkylsubstituent of the alkyelenediamine or the polyalkylenediamine by analkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group having 2to 4 carbon atoms such as dialkylaminopropylamine,trimethylhexamethylenediamine, aminoethylethanolamine,2,5-dimethyl-2,5-hexamethylenediamine and methyliminobispropylamine; analicyclic diamine having 4 to 15 carbon atoms such as1,3-diaminocyclohexane, isophorone diamine, menthenediamine and4,4′-methylenedichylohexanediamine (hydrogenated methylenedianiline); aheterocyclic diamine having 4 to 15 carbon atoms such as piperazine,N-aminoethylpiperazine, 1,4-diaminoethylpiperazine,1,4-bis(2-amino-2-methylpropyl)piperazine,3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, andaliphatic amines including an aromatic ring having 8 to 15 carbon atomssuch as xylylenediamine and tetrachloro-p-xylylenediamine.

The aromatic diamines having 6 to 20 carbon atoms are not particularlyrestricted and may be appropriately selected according to purpose.Examples thereof include; non-substituted aromatic diamines such as1,2-, 1,3- and 1,4-phenylenediamine, 2,4′- and4,4′-diphenylmethanediamine, crude diphenylmethanediamine(polyphenylpolymethylenepolyamine), diaminodiphenyl sulfone, benzidine,thiodianiline, bis(3,4-di-aminophenyl)sulfone, 2,6-diaminopyridine,m-aminobenzylamine, triphenylmethane-4,4′,4″-triamine andnaphthylenediamine; aromatic diamines having nuclear-substituted alkylgroup having 1 to 4 carbon atoms such as 2,4- and2,6-triethylenediamine, crude tolylenediamine, diethyltolylenediamine,4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-bis(o-toluidine),dianisidine, diaminoditolyl sulfone, 1,3-dimethyl-2,4-diaminobenzene,1,3-dimethyl-2,6-diaminobenzene, 1,4-diisopropyl-2,5-diaminobenzene,2,4-diaminomesitylene, 1-methyl-3,5-diethyl-2,4-diaminobenzene,2,3-dimethyl-1,4-diaminonaphthalene,2,6-dimethyl-1,5-diaminonaphthalene, 3,3′,5,5′-tetramethylbenzidine,3,3′,5,5′-tetramethyl-4,4′-diaminodiphenylmethane,3,5-diethyl-3′-methyl-2′,4-diaminodiphenylmethane,3,3′-diethyl-2,2′-diaminodiphenylmethane,4,4′-diamino-3,3′-dimethyldiphenylmethane,3,3′,5,5′-tetraethyl-4,4′-diaminobenzophenone,3,3′,5,5′-tetraethyl-4,4′-diamino diphenyl ether and3,3′,5,5′-tetraisopropyl-4,4′-diaminodiphenyl sulfone; mixtures ofvarious ratios of the unsubstituted aromatic diamines or isomers of thearomatic diamines having nuclear-substituted alkyl group having 1 to 4carbon atoms; methylenebis-o-chloroaniline, 4-chloro-o-phenylenediamine,2-chloro-1,4-phenylenediamine, 3-amino-4-chloroaniline,4-bromo-1,3-pehnylenediamine, 2,5-dichloro-1,4-phenylenediamine,5-nitro-1,3-phenylenediamine and 3-dimethoxy-4-aminoaniline; aromaticdiamines having nuclear substituted electron-withdrawing group (forexample, halogens such as Cl, Br, I and F; alkoxy group such as methoxyand ethoxy groups; and nitro group) such as4,4′-diamino-3,3′-dimethyl-5,5′-dibromodiphenylmethane,3,3′-dichlorobenzidine, 3,3′-dimethoxybenzidine,bis(4-amino-3-chlorophenyl)oxide, bis(4-amino-2-chlorophenyl)propane,bis(4-amino-2-chlorophenyl) sulfone, bis(4-amino-3-methoxyphenyl)decane,bis(4-aminophenynsulfide, bis(4-aminophenyl)telluride,bis(4-aminophenyl)selenide, bis(4-amino-3-methoxyphenyl)disulfide,4,4′-methylenebis(2-iodoaniline), 4,4′-methylenebis(2-bromoaniline),4,4′-methylenebis(2-fluoroaniline) and 4-aminophenyl-2-chloroaniline;and aromatic diamines having a secondary amino group such as4,4′-di(methylamino)diphenylmethane and1-methyl-2-methylamino-4-aminobenzene [a part or all the primary aminogroup of the non-substituted aromatic diamine, the aromatic diaminehaving a nuclear-substituted alkyl group having 1 to 4 carbon atoms anda mixture of isomers thereof with various mixing ratios, and thearomatic diamine having a nuclear-substituted electron-withdrawing groupis replaced by a secondary amino group with a lower alkyl group such asmethyl and ethyl groups].

Other examples of the diamines include: polyamide polyamines such aslow-molecular polyamide polyamine obtained by condensation of adicarboxylic acid (e.g. dimer acid) with an excess amount of thepolyamine (e.g. the alkylenediamine and the polyalkylenepolyamine); anda polyether polyamine such as hydrate of cyanoethylated polyether polyol(e.g. polyalkylene glycol).

Also, an amine compound whose amino group is capped with a ketonecompound may be used.

Among these polyurea units, the polyurea unit synthesized from thediamine and the diisocyanate is preferable.

Examples of the diisocyanate and the polyisocyanate having 3 or morevalences are similar to those diisocyanates and polyisocyanates having 3or more valences.

—Vinyl Polymer Unit—

The vinyl polymer unit is a polymer unit that a vinyl monomer ishomopolymerized or copolymerized. The vinyl monomer is not particularlyrestricted and may be appropriately selected according to purpose.Examples thereof include those of (1) to (10) below.

(1) Vinyl Hydrocarbons:

Aliphatic vinyl hydrocarbon: alkenes, e.g. ethylene, propylene, butane,isobutylene, pentene, heptene, diisobutylene, octane, dodecene,octadecene and other α-olefines; alkadiene, e.g. butadiene, isoprene,1,4-pentadiene, 1,6-hexadiene and 1,7-octadiene.

Alicyclic vinyl hydrocarbon: mono- or di-cycloalkenes and alkadienes,e.g. cyclohexane, (di)cyclopentadiene, vinylcyclohexene andethylidenebicycloheptene; terpenes, e.g. pinene, limonene and indene.

Aromatic vinyl hydrocarbon: styrene and hydrocarbyl (alkyl, cycloalkyl,aralkyl and/or alkenyl) substituents thereof, e.g. α-methylstyrene,vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene,butylstyrene, phenylstyrene, cyclohexylstyrene, benzylstyrene,crotylbenzene, divinylbenzene, divinyltoluene, divinylxylene andtrivinylbenzene; and vinylnaphthalene.

(2) Vinyl Monomers Including Carboxyl Group and Salt Thereof:

Unsaturated monocarboxylic acid having 3 to 30 carbon atoms, unsaturateddicarboxylic acid and anhydride thereof and monoalkyl ester (1 to 24carbon atoms) thereof, e.g. vinyl monomer including carboxyl group suchas (meth)acrylic acid, maleic acid, maleic anhydride, maleic acidmonoalkyl ester, fumaric acid, fumaric acid monoalkyl ester, crotonicacid, itaconic acid, itaconic acid monoalkyl ester, itaconic acid glycolmonoether, citraconic acid, citraconic acid monoalkyl ester and cinnamicacid.

(3) Vinyl Monomers Including Sulfonic Group, Vinyl Sulfuric AcidMonoesters, and Salts Thereof:

Alkene sulfonic acids having 2 to 14 carbon atoms, e.g. vinylsulfonicacid, (meth)allylsulfonic acid, methylvinylsulfonic acid andstyrenesulfonic acid; alkyl derivatives thereof having 2 to 24 carbonatoms, e.g. α-methylstyrene sulfonic acid;sulfo(hydroxyl)alkyl-(meth)acrylate or (meth)acrylamide, e.g.sulfopropyl (meth) acrylate, 2-hydroxy-3-(meth)acryloxypropyl sulfonicacid, 2-(meth)acryloylamino-2,2-dimethylethane sulfonic acid,2-(meth)acryloyloxyethane sulfonic acid,3-(meth)acryloyloxy-2-hydroxypropane sulfonic acid,2-(meth)acrylamide-2-methylpropane sulfonic acid,3-(meth)acrylamide-2-hydroxypropane sulfonic acid,alkylarylsulfosuccinic acid (3 to 18 carbon atoms in the alkyl group),sulfate ester of polyoxyalkylene mono(meth)acrylate (n=2 to 30)(ethylene, propylene, butylene: alone, random or block) [e.g. sulfateester of polyoxypropylene monomethacrylate (n=5 to 15)], and sulfuricester of polyoxyethylene polycyclic phenyl ether.

(4) Vinyl Monomers Including Phosphate Group and Salt Thereof.

(Meth)acryloyloxy alkyl phosphate monoester, e.g. 2-hydroxyethyl(meth)acryloyl phosphate, phenyl-2-acryloyloxyethyl phosphate,(meth)acryloyloxyalkyl phosphoric acid (1 to 24 carbon atoms in thealkyl group) (e.g. 2-acryloyloxyethyl phosphoric acid); and saltsthereof.

Here, examples of the salts of (2) to (4) above include alkali metalsalts (e.g. sodium salt and potassium salt), alkaline earth metal salts(e.g. calcium salt and magnesium salt), ammonium salt, amine salt andquaternary ammonium salt.

(5) Vinyl Monomers Including Hydroxyl Group:

Hydroxystyrene, N-methylol(meth)acrylamide, hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, polyethylene glycol mono(meth)acrylate,(meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol,2-butene-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethylpropenyl ether and sucrose allyl ether.

(6) Vinyl Monomers Including Nitrogen:

Vinyl monomer including amino group: aminoethyl (meth)acrylate,dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth)acrylate,t-butylaminoethyl methacrylate, N-aminoethyl (meth)acrylamide,(meth)arylamine, morpholinoethyl (meth)acrylate, 4-vinylpyridine,2-vinylpyridine, crotylamine, N,N-dimethylaminostyrene,methyl-α-acetamino acrylate, vinyl imidazole, N-vinylpyrrole,N-vinylthiopyrrolidone, N-arylphenylenediamine, aminocarbazole,aminothiazole, aminoindole, aminopyrrole, aminoimidazole,aminomercaptothiazole, and salts thereof.

Vinyl monomer including amide group: (meth)acrylamide,N-methyl(meth)acrylamide, N-butylacrylamide, diacetoneacrylamide,N-methylol(meth)acrylamide, N,N-methylene-bis(meth)acrylamide, cinnamicacid amide, N,N-dimethylacrylamide, N,N-dibenzylacrylamide,methacrylformamide, N-methyl-N-vinylacetamide and N-vinylpyrrolidone.

Vinyl monomer including nitrile group: (meth)acrylonitorile,cyanostyrene and cyanoacrylate.

Vinyl monomer including quaternary ammonium cation group quaternarizedvinyl monomer including tertiary amine group such as dimethylaminoethyl(meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl(meth)acrylamide, diethylaminoethyl (meth)acrylamide and diarylamine(quaternarized product using quaternarizing agent such as methylchloride, dimethyl sulfate, benzyl chloride and dimethyl carbonate).

Vinyl monomer including nitro group: nitrostyrene.

(7) Vinyl Monomers Including Epoxy Group:

Glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate andp-vinylphenyl phenyl oxide.

(8) Vinyl Esters, Vinyl (Thio)Ethers, Vinyl Ketones, Vinyl Sulfones:

Vinyl ester: vinyl acetate, vinyl propionate, vinyl butyrate, diallylphthalate, diallyl adipate, isopropenyl acetate, vinyl methacrylate,methyl-4-vinylbenzoate, cyclohexyl methacrylate, benzyl methacrylate,phenyl (meth) acrylate, vinyl methoxyacetate, vinyl benzoate,ethyl-α-ethoxy acrylate, alkyl (meth)acrylate having 1 to 50 carbonatoms [e.g. methyl (meth)acrylate, ethyl (meth)acrylate, propyl(meth)acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth)acrylate,dodecyl (meth) acrylate, hexadecyl (meth)acrylate, heptadecyl(meth)acrylate and eicosyl (meth)acrylate], dialkyl fumarate (two alkylgroups are a straight-chain, a branched-chain or an alicyclic grouphaving 2 to 8 carbon atoms), dialkyl maleate (two alkyl groups are astraight-chain, a branched-chain or an alicyclic group having 2 to 8carbon atoms), poly(meth)allyloxyalkanes [e.g. diallyloxyethane,triallyloxyethane, tetraallyloxyethane, tetraallyloxypropane,tetraallyloxybutane and tetramethallyloxyethane], vinyl monomer havingpolyalkylene glycol chain [e.g. polyethylene glycol (molecular weight of300) mono(meth)acrylate, polypropylene glycol (molecular weight of 500)monoacrylate, methyl alcohol ethylene oxide 10-mole adduct of(meth)acrylate, lauryl alcohol ethylene oxide 30-mole adduct of(meth)acrylate], and poly(meth)acrylates [poly(meth)acrylates ofpolyhydric alcohols: ethylene glycol di(meth)acrylate, propylene glycoldi(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropanetri(meth)acrylate and polyethylene glycol di(meth)acrylate].

Vinyl (thio)ether: vinyl methyl ether, vinyl ethyl ether, vinyl propylether, vinyl butyl ether, vinyl 2-ethylhexyl ether, vinyl phenyl ether,vinyl 2-methoxyethyl ether, methoxybutadiene, vinyl 2-butoxyethyl ether,3,4-dihydro-1,2-pyran, 2-butoxy-2′-vinyloxy diethyl ether, vinyl-2-ethylmercaptoethyl ether, acetoxystyrene and phenoxy styrene.

Vinyl ketone: vinyl methyl ketone, vinyl ethyl ketone, vinyl phenylketone.

Vinyl sulfones: divinyl sulfide, p-vinyldiphenyl sulfide, vinyl ethylsulfide, vinyl ethyl sulfone, divinyl sulfone and divinyl sulfoxide.

(9) Other Vinyl Monomers:

Isocyanatoethyl (meth)acrylate and m-isopropenyl-α,α′-dimethylbenzylisocyanate.

(10) Vinyl Monomers Including Elemental Fluorine Atom:

4-Fluorostyrene, 2,3,5,6-tetrafluorostyrene, pentafluorophenyl(meth)acrylate, pentafluorobenzyl (meth) acrylate, perfluorocyclohexyl(meth)acrylate, perfluorocyclohexylmethyl (meth)acrylate,2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,4H-hexafluorobutyl (meth)acrylate,1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,7H-dodecafluoroheptyl(meth)acrylate, perfluorooctyl (meth)acrylate, 2-perfluorooctylethyl(meth)acrylate, heptadecafluorodecyl (meth)acrylate,trihydroperfluoroundecyl (meth)acrylate, perfluoronorbornylmethyl(meth)acrylate, 1H-perfluoroisobornyl (meth)acrylate,2-(N-butylperfluorooctane sulfonamide)ethyl (meth)acrylate andcorresponding compounds derived from α-fluoroacrylic acid,bis-hexafluoroisopropyl itaconate, bis-hexafluoroisopropyl maleate,bis-perfluorooctyl itaconate, bis-perfluorooctyl maleate,bis-trifluoroethyl itaconate and bis-trifluoroethyl maleate,vinylheptafluoro butyrate, vinylperfluoroheptanoate,vinylperfluoronanoate and vinylperfluoro octanoate.

<<<Crystalline Resin Including Urea Bond>>>

The crystalline resin preferably includes a crystalline resin includinga urea bond in a main chain thereof. According to Solubility ParameterValues (Polymer handbook 4th Ed), a urea bond has a cohesive energy of50,230 [J/mol], which is about twice as large as a cohesive energy of aurethane bond (26,370 [J/mol]). Thus, an effect of improving toughnessor resistance to offset of a toner during fixing may be expected evenwith a small amount.

Examples of a method for preparing the crystalline resin having a ureabond include: a method to react a polyisocyanate compound and apolyamine compound; and a method to react a polyisocyanate compound withwater and reacting an amino group generated by a hydrolysis of theisocyanate with a remaining isocyanate group. Also, when the crystallineresin including a urea bond is prepared, the resin may be designed withhigher degree of freedom by reacting a polyol compound simultaneously inaddition to the above compounds.

—Polyisocyanate—

As the polyisocyanate, in addition to the diisocyanate and thepolyisocyanate having 3 or more valences (hereinafter, also referred toas a low-molecular weight polyisocyanate), a polymer having anisocyanate group at an end or a side chain thereof (hereinafter, alsoreferred to as a prepolymer) may also be used.

Examples of a method for preparing the prepolymer include: a method forobtaining a polyurea prepolymer having an isocyanate group at an endthereof by reacting the low-molecular weight polyisocyanate and apolyamine compound described hereinafter with an excess amount of theisocyanate; and a method for obtaining a prepolymer having an isocyanategroup at an end thereof by reacting the low-molecular weightpolyisocyanate and the polyol compound with an excess amount of theisocyanate. The prepolymers obtained by these methods may be used alone,or two or more types of the prepolymers obtained by the same method ortwo or more types of the prepolymers obtained by the two methods may beused in combination. Moreover, the prepolymer and one type or varioustypes of the low-molecular weight polyisocyanates may be used incombination.

A use ratio of the polyisocyanate, as an equivalent ratio [NCO]/[NH₂] ofthe isocyanate group [NCO] and the amino group [NH₂] in the polyamine oras an equivalent ratio [NCO]/[OH] of the isocyanate group [NCO] and thehydroxyl group [OH] in the polyol, is usually 5/1 to 1.01/1, preferably4/1 to 1.2/1, and more preferably 2.5/1 to 1.5/1.

When the molar ratio of [NCO] exceeds 5, urethane bonds and urea bondsare present in excess. When a resin obtained in the end is used as abinder resin for a toner, excessively high elasticity in a molten statemay degrade fixing property. When the molar ratio of [NCO] is less than1.01, too high degree of polymerization increases the molecular weightof the prepolymer, which is not preferable because it is difficult tomix it with the other materials for manufacturing a toner or becauseexcessively high elasticity in a molten state may degrade fixingproperty.

—Polyamine—

Examples of the polyamine include the diamines and the polyamines havingthree or more valences described above.

—Polyol—

As the polyol, in addition to the polyol having 3 to 8 valences or more(hereinafter referred to also as a low-molecular weight polyol)described above, a polymer having a hydroxyl group at an end or a sidechain thereof (hereinafter referred to as a high-molecular weightpolyol) may be used.

Examples of a method for preparing the high-molecular weight polyolinclude: a method to obtain polyurethane having a hydroxyl group at anend thereof by reacting a low-molecular weight polyisocyanate and alow-molecular weight polyol with an excess amount of hydroxyl group; anda method to obtain polyester having a hydroxyl group at an end thereofby reacting a polycarboxylic acid and a low-molecular weight polyolcompound with an excess amount of hydroxyl group.

For preparing the polyurethane or the polyester having a hydroxyl groupat an end thereof, a ratio of the low-molecular weight polyol to thelow-molecular weight polyisocyanate [OH]/[NCO] or a ratio of thelow-molecular weight polyol to the polycarboxylic acid [OH]/[COOH] isusually 2/1 to 1/1, preferably 1.5/1 to 1/1, and more preferably 1.3/1to 1.02/1.

When the molar ratio of the hydroxyl group exceeds 2, polymerizationreaction does not proceed, and a desired high-molecular weight polyol isnot obtained. When it is below 1.02, the degree of polymerizationincreases, causing too much increase in the molecular weight of aobtained high-molecular weight polyol. This is not preferable because itis difficult to mix it with the other materials for manufacturing atoner or because excessively high modulus of elasticity in a moltenstate may degrade fixing property.

—Polycarboxylic Acid—

Examples of the polycarboxylic acid include the dicarboxylic acid andthe polycarboxylic acid having 3 to 6 valences or more described above.

In order for the obtained resin having a urea bond to havecrystallinity, a polymer unit having crystallinity may be introduced toa main chain thereof. Examples of the crystalline polymer unit having afavorable melting point as a binder resin for a toner include thecrystalline polyester unit and a long-chain alkyl ester unit ofpolyacrylic acid and methacrylic acid described above. The crystallinepolymer unit is preferable since it enables easy preparation of a resinwith terminal alcohol and, as a polyol compound, easy introduction tothe resin having a urea bond.

Examples of the crystalline polyester unit include a polycondensationpolyester unit, a lactone ring-opening polymerization product and apolyhydroxycarboxylic acid synthesized from a polyol and apolycarboxylic acid. Among these, a polycondensation polyester unit ofdiol and dicarboxylic acid is preferable in view of developingcrystallinity.

As the diol, diols exemplified for the polyol described above may beused. Among them, the aliphatic diol having 2 to 36 chain carbon atomsis preferable, and the straight-chain aliphatic diol is more preferable.These may be used alone or in combination of two or more. Among these,ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol,1,9-nonanediol and 1,10-decanediol are preferable considering easyavailability.

A content of the straight-chain aliphatic diol with respect to the wholediol is preferably 80% by mole or greater, and more preferably 90% bymole or greater. The amount is 80% by mole or greater is preferablesince both low-temperature fixing property and heat-resistant storagestability may be favorably achieved and the resin tends to have improvedhardness.

As the dicarboxylic acid, those dicarboxylic acids exemplified for thepolycarboxylic acid may be used. Among these, the straight-chaindicarboxylic acid is more preferable.

Among the dicarboxylic acids, the aliphatic dicarboxylic acid alone(preferably adipic acid, sebacic acid or dodecane dicarboxylic acid) isparticularly preferable. Similarly, it is preferable that the aliphaticdicarboxylic acid and the aromatic dicarboxylic acid (preferablyterephthalic acid, isophthalic acid and t-butylisophthalic acid; andlower alkyl esters of these aromatic dicarboxylic acids) arecopolymerized. An amount of copolymerization of the aromaticdicarboxylic acid is preferably 20% by mole or less.

[Introduction of Crystalline Resin Having Urea Bond to Toner]

A toner may be obtained by using a resin in which a urea bond is formedbeforehand as a binder resin, which is mixed with toner constitutingmaterials other than the binder resin such as colorant, releasing agentand charge controlling agent and granulated. The urea bond may be formedby mixing a polyisocyanate compound and a polyamine compound and/orwater, and other toner constituting materials other than the binderresin such as colorant, releasing agent and charge controlling agentaccording to necessity. Especially, use of the polyisocyanate compoundas a prepolymer is preferable since a crystalline resin having a ureabond and a high-molecular weight may be introduced uniformly in thetoner, the toner has uniform thermal properties and charging propertyand the toner may achieve both fixing property and stress resistance.Further, as the prepolymer, a prepolymer obtained by reacting alow-molecular weight polyisocyanate and a polyol compound with an excessamount of the isocyanate is preferable since it may reduceviscoelasticity. As the polyol compound, polyester having hydroxyl groupat an end thereof obtained by reacting a polycarboxylic acid and alow-molecular polyol compound with an excess amount of hydroxyl group ispreferable since thermal properties suitable for the toner may be easilyobtained. Moreover, polyester consisting of a crystalline polyester unitis preferable since a high molecular weight component in the toner hassharp melt property, resulting in excellent low-temperature fixingproperty.

Also, when the toner of the present invention is obtained by granulationin an aqueous medium, the urea bond may be formed under mild conditionsbecause water as the dispersing medium reacts with the polyisocyanatecompound.

The crystalline resin may be used alone or in combination of two ormore. Also, the crystalline resin may be used in combination withanother crystalline resin having a different weight-average molecularweight. It is preferable to include at least a first crystalline resinand a second crystalline resin having a weight-average molecular weightgreater than that of the first crystalline resin since both superiorlow-temperature fixing property and heat-resistant storage stability maybe obtained.

In view of achieving both low-temperature fixing property andheat-resistant storage stability, the first crystalline resin has aweight-average molecular weight (Mw1) of preferably 10,000 to 40,000,more preferably 15,000 to 35,000 and particularly preferably 20,000 to30,000. The toner with Mw1 of less than 10,000 tends to have degradedheat-resistant storage stability, and the toner with Mw1 exceeding40,000 tends to have degraded low-temperature fixing property, which arenot preferable.

In view of achieving both low-temperature fixing property andheat-resistant storage stability, the second crystalline resin has aweight-average molecular weight (Mw2) of preferably 40,000 to 300,000,and particularly preferably 50,000 to 150,000. The toner having the Mwof less than 40,000 tends to have degraded hot-offset resistance, andthe toner having the Mw exceeding 300,000 tends to have degradedlow-temperature fixing property since the toner does not sufficientlymelt in fixing particularly at a low temperature, easily causing peelingof images, which are not preferable.

A difference (Mw2−Mw1) between the weight-average molecular weight ofthe first crystalline resin (Mw1) and the weight-average molecularweight of the second crystalline resin (Mw2) is not particularlyrestricted and may be appropriately selected according to purpose. It ispreferably 5,000 or greater, and more preferably 10,000 or greater. Thedifference of less than 5,000 is not preferable since the toner tends tohave a narrow fixing range.

A mass ratio [(1)/(2)] of the first crystalline resin (1) and the secondcrystalline resin (2) is not particularly restricted and may beappropriately selected according to purpose. It is preferably 95/5 to70/30. The toner having the ratio exceeding 95/5 tends to have degradedhot-offset resistance, and the toner having the ratio of less than 70/30tends to have degraded low-temperature fixing property, which are notpreferable.

The second crystalline resin may also be obtained in a process ofmanufacturing a toner by reacting a crystalline resin precursor having afunctional group reactive with an active hydrogen group at an endthereof with a resin having an active hydrogen group or a compound suchas crosslinking agent and elongating agent having an active hydrogengroup so as to increase the molecular weight.

The crystalline resin precursor may be obtained by reacting thecrystalline polyester resin, urethane-modified crystalline polyesterresin, urea-modified crystalline polyester resin, crystallinepolyurethane resin or a crystalline polyurea resin with a compoundhaving a functional group reactive with an active hydrogen group.

The compound having a functional group reactive with an active hydrogengroup is not particularly restricted and may be appropriately selectedaccording to purpose. Examples of the functional group include anisocyanate group, an epoxy group, carboxylic acid and an acid chloridegroup. Among these, an isocyanate group is preferable in view ofreactivity and stability. Examples of the compound having an isocyanategroup include the diisocyanate components.

When the crystalline polyester resin is reacted with the diisocyanatecomponent to obtain the crystalline resin precursor, it is preferable touse a hydroxyl group-containing crystalline polyester resin having ahydroxyl group at an end thereof as the crystalline polyester resin. Thehydroxyl group-containing crystalline polyester resin may be obtained byreacting a diol and dicarboxylic acid with a ratio of the diol componentand the dicarboxylic acid component as an equivalent ratio [OH]/[COOH]of the hydroxyl group [OH] to the carboxyl group [COOH] of preferably2/1 to 1/1, more preferably 1.5/1 to 1/1, and particularly preferably1.3/1 to 1.02/1.

Regarding a used amount of the compound having a functional groupreactive with an active hydrogen group, when the crystalline resinprecursor is obtained by reacting the hydroxyl group-containingcrystalline polyester resin with a diisocyanate component, a ratio ofthe diisocyanate component, as an equivalent ratio [NCO]/[OH] of thediisocyanate group [NCO] to the hydroxyl group [OH] of the hydroxylgroup-containing crystalline polyester resin is preferably 5/1 to 1/1,more preferably 4/1 to 1.2/1 and particularly preferably 2.5/1 to 1.5/1.In the cases of crystalline resin precursors having other skeletons orterminal groups, a ratio is similar only with different constitutionalcomponents.

The resin having an active hydrogen group and the compound such ascrosslinking agent and elongation agent having an active hydrogen groupare not particularly restricted and may be appropriately selectedaccording to purpose. Examples thereof include resins and compoundshaving a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxylgroup), an amino group, a carboxyl group or a mercapto group for a casewhere the functional group reactive with the active hydrogen group is anisocyanate group. Among these, water and amines are particularlypreferable.

Also, the second crystalline resin is obtained preferably by using amodified crystalline resin including an isocyanate group at an endthereof as the crystalline resin precursor and reacting it with acompound having an active hydrogen group for elongation. In this case,the reaction of the crystalline resin precursor and the compound havingan active hydrogen group is preferably carried out in a process ofmanufacturing a toner. Thereby, the crystalline resin having a largeweight-average molecular weight may be uniformly dispersed in the toner,and variation in the properties among toner particles may be suppressed.

Further, the first crystalline resin is preferably κ crystalline resinincluding a urethane bond or a urea bond or both thereof in a main chainthereof, and the second crystalline resin is preferably κ crystallineresin obtained by reacting the crystalline resin precursor as amodification of the first crystalline resin with a compound having anactive hydrogen group for elongation. When the first crystalline resinand the second crystalline resin have similar compositions andstructures, these two different binder resins may be more uniformlydispersed in the toner, and as a result variation in the propertiesamong toner particles may be suppressed.

As the binder resin, a combination of the crystalline resin and anon-crystalline resin may be used, and it is preferable that thecrystalline resin is a main component of the binder resin.

<<Non-Crystalline Resin>>

The non-crystalline resin is not particularly restricted as long as itis non-crystalline, and it may be appropriately selected according topurpose. Examples thereof include: a homopolymer of styrene and asubstitution product thereof such as polystyrene and polyvinyltoluene; astyrene copolymer such as styrene-methyl acrylate copolymer,styrene-methacrylic acid copolymer, styrene-methyl methacrylatecopolymer, styrene-butyl methacrylate copolymer, styrene-acrylonitrilecopolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methylketone copolymer, styrene-butadiene copolymer and styrene-maleic acidester copolymer; a polymethyl methacrylate resin, a polybutylmethacrylate resin, a polyvinyl acetate resin, a polyethylene resin, apolyester resin, a polyurethane resin, an epoxy resin, a polyvinylbutyral resin, a polyacrylic resin, a rosin resin, a modified rosinresin, and these resins modified to have a functional group reactivewith an active hydrogen group. These may be used alone or in combinationof two or more.

A content of the non-crystalline resin in the binder resin is notparticularly restricted and may be appropriately selected according topurpose.

<Colorant>

A colorant used for a toner of the present invention is not particularlyrestricted and may be appropriately selected from heretofore knowncolorants according to purpose.

A color of the colorant of the toner is not particularly restricted andmay be appropriately selected according to purpose. It may be at leastone type selected from black, cyan, magenta and yellow. A toner ofrespective color may be obtained by appropriately selecting the type ofthe colorant, and it is preferably κ color toner.

Examples of a black colorant include: carbon blacks (C.I. Pigment Black7) such as furnace black, lamp black, acetylene black and channel black;metals such as copper, iron (C.I. Pigment Black 11), and titanium oxide;and organic pigments such as aniline black (C.I. Pigment Black 1).

Examples of a magenta colorant include: C.I. Pigment Red 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31,32, 37, 38, 39, 40, 41, 48, 48:1, 49, 50, 51, 52, 53, 53:1, 54, 55, 57,57:1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123,150, 163, 177, 179, 184, 202, 206, 207, 209, 211, 269; C.I. PigmentViolet 19; and C. I. Vat Red 1, 2, 10, 13, 15, 23, 29, 35.

Examples of a cyan colorant include: C. I. Pigment Blue 2, 3, 15, 15:1,15:2, 15:3, 15:4, 15:6, 16, 17, 60; C.I. Vat Blue 6; C.I. Acid Blue 45,copper phthalocyanine pigment with its phthalocyanine skeletonsubstituted with 1 to 5 phthalimidomethyl groups, Green 7 and Green 36.

Examples of a yellow colorant include: C. I. Pigment Yellow 1, 2, 3, 4,5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 55, 65, 73, 74, 83, 97,110, 139, 151, 154, 155, 180, 185; C. I. Vat Yellow 1, 3, 20, and Orange36.

A content of the colorant in the toner is preferably 1% by mass to 15%by mass, and more preferably 3% by mass to 10% by mass. When the contentis less than 1% by mass, coloring strength of the toner may degrade.When it exceeds 15% by mass, the pigment is poorly dispersed in thetoner, which may result in decreased coloring strength and decreasedelectrical properties.

The colorant may be used as a masterbatch as a composite of the colorantand a resin. Such a resin is not particularly restricted, but it ispreferable to use a binder resin of the present invention or a resinhaving a similar structure to a binder resin of the present invention inview of compatibility with the binder resin of the present invention.

The masterbatch may be manufactured by mixing or kneading the resin andthe colorant with an application of high shear force. To enhance aninteraction between the colorant and the resin, an organic solvent ispreferably added. Also, a so-called flushing method is favorable since awet cake of the colorant may be used as it is, without necessity ofdrying. The flushing method is a method of mixing or kneading an aqueouspaste of the colorant including water with a resin and an organic mediumto remove the water and the organic medium by transferring the colorantto the resin. For mixing or kneading, for example, a high sheardispersing apparatus such as three-roll mill may be used.

<Releasing Agent>

The releasing agent is not particularly restricted and may beappropriately selected according to purpose. Examples thereof includewaxes such as wax including a carbonyl group, polyolefin wax andlong-chain hydrocarbon. These may be used alone or in combination of twoore more. Among these, a wax including a carbonyl group is preferable.

Examples of the wax including a carbonyl group include polyalkanoic acidester, polyalkanol ester, polyalkanoic acid amide, polyalkyl amide anddialkyl ketone.

Examples of the polyalkanoic acid ester include carnauba wax, montanwax, trimethylolpropane tribehenate, pentaerythritol tetra behenate,pentaerythritol diacetate dibehenate, glycerin tribehenate and1,18-octadecanediol distearate.

Examples of the polyalkanol ester include trimellitic acid tristearyland distearyl maleate.

Examples of the polyalkanoic acid amide include dibehenyl amide.

Examples of the polyalkyl amide include trimellitic acid tristearylamide.

Examples of the dialkyl ketone include distearyl ketone.

Among these waxes including a carbonyl group, a polylalkanoic acid esteris particularly preferable.

Examples of the polyolefin wax include polyethylene wax andpolypropylene wax.

Examples of the long-chain hydrocarbon include paraffin wax and Sasolwax.

A melting point of the releasing agent is not particularly restrictedand may be appropriately selected according to purpose. It is preferably50° C. to 100° C., and more preferably 60° C. to 90° C. The meltingpoint of less than 50° C. may adversely affect heat-resistant storagestability, and the melting point exceeding 100° C. may cause cold offsetduring low-temperature fixing.

The melting point of the releasing agent may be measured using adifferential scanning calorimeter (TA-60WS and DSC-60 (manufactured byShimadzu Corporation)), for example. That is, first, 5.0 mg of thereleasing agent is placed in a sample container made of aluminum, andthe sample container is placed on a holder unit and set in an electricfurnace. Next, it is heated from 0° C. to 150° C. at a heating rate of10° C./min in a nitrogen atmosphere. Thereafter, it is cooled from 150°C. to 0° C. at a cooling rate of 10° C./min and then heated from 0° C.to 150° C. at a heating rate of 10° C./min, and a DSC curve is measured.From the obtained DSC curve, a maximum peak temperature of heat offusion in the second temperature increase may be obtained as the meltingpoint using an analysis program in the DSC-60 system.

A melt viscosity of the releasing agent is preferably 5 mPa sec to 100mPa sec, more preferably 5 mPa sec to 50 mPa sec, and particularlypreferably 5 mPa-sec to 20 mPa sec. The melt viscosity of less than 5mPa sec may degrade releasing property, and the melt viscosity exceeding100 mPa sec may degrade hot-offset resistance and releasing property ata low temperature, which are not preferable.

A content of the releasing agent in the toner is not particularlyrestricted and may be appropriately selected according to purpose. It ispreferably 1% by mass to 20% by mass, and more preferably 3% by mass to10% by mass. The content of less than 1% by mass tends to degradehot-offset resistance, and the content exceeding 20% by mass tends todegrade heat-resistant storage stability, charging property, transferproperty and stress resistance, which are not preferable.

<Other Components>

Examples of the other components include a charge controlling agent, anexternal additive, a fluidity improving agent, a cleanability improvingagent and a magnetic material.

<<Charge Controlling Agent>>

It is also possible to include a charge controlling agent in a toneraccording to necessity to impart adequate charging ability to the toner.

As the charge controlling agent, any of heretofore known chargecontrolling agent may be used. Since a color tone may change when acolored material is used, the charge controlling agent is preferablyclose to white or colorless. Examples thereof include triphenylmethanedyes, molybdic acid chelate pigments, rhodamine dyes, alkoxy amine,quaternary ammonium salt (including fluorine-modified quaternaryammonium salts), alkyl amide, elemental phosphorus or its compounds,elemental tungsten or its compounds, fluorine surfactants, metal saltsof salicylic acid and metal salts of salicylic acid derivatives. Thesemay be used alone or in combination of two or more.

A content of the charge controlling agent is determined by a tonermanufacturing method, including types of the binder resin and adispersing method, and it is not limited unambiguously. Nonetheless, itis preferably 0.01% by mass to 5% by mass, and more preferably 0.02% bymass to 2% by mass with respect to the binder resin. When the contentexceeds 5% by mass, charging property of the toner is too large, therebyweakening an effect of the charge controlling agent, and anelectrostatic attraction force with a developing roller increases,resulting in decreased fluidity of a developer and decreased imagedensity. When the content is less than 0.01% by mass, charge risingproperty and charge amount are insufficient, which may affect a tonerimage.

<<External Additive>>

Various external additives may be added to the toner of the presentinvention for the purpose of fluidity improvement, charge amountadjustment and electric property adjustment. The external additives arenot particularly restricted and may be appropriately selected accordingto purpose. Examples thereof include: silica particles, hydrophobizedsilica particles and fatty acid metal salt (e.g. zinc stearate andaluminum stearate); and metal oxides (e.g. titania, alumina, tin oxideand antimony oxide) or hydrophobized products thereof. Among these,hydrophobized silica particles, titania and hydrophobized titaniaparticles are preferable.

Examples of the hydrophobized silica particles include: HDK H2000, HDKH2000/4, HDK H2050EP, HVK21 and HDK H1303 (manufactured by ClariantCorporation); and R972, R974, RX200, RY200, R202, R805 and R812(manufactured by Nippon Aerosil Co., Ltd.). Examples of the titaniaparticles include: P-25 (manufactured by Nippon Aerosil Co., Ltd.);STT-30 and STT-65C-S (manufactured by Titan Kogyo Co., Ltd.); TAF-140(manufactured by Fuji Titanium Industry Co., Ltd.); and MT-150 W,MT-500B, MT-600B and MT-150A (manufactured by Tayca Corporation).Examples of the hydrophobized titanium oxide particles include: T-805(manufactured by Nippon Aerosil Co., Ltd.); STT-30A, STT-65S-S(manufactured by Titan Kogyo Co., Ltd.); TAF-500T, TAF-1500T(manufactured by Fuji Titanium Industry Co., Ltd.); MT-100 S, MT-100T(manufactured by Tayca Corporation); and IT-S (manufactured by IshiharaSangyo Kaisha, Ltd.).

The hydrophobized silica particles, the hydrophobized titania particlesand the hydrophobized alumina particles may be obtained by treatinghydrophilic particles with a silane coupling agent such asmethyltrimethoxysilane, methyltriethoxysilane and octyltrimethoxysilane.Examples of the hydrophobizing agent include a silane coupling agentsuch as dialkyl dihalogenated silane, trialkyl halogenated silane, alkyltrihalogenated silane and hexaalkyl disilazane, a silylating agent, asilane coupling agent having a fluorinated alkyl group, organic titanatecoupling agent, aluminum coupling agent, silicone oil and siliconevarnish.

Primary particles of the inorganic particles have an average particlediameter of preferably 1 nm to 100 nm, and more preferably 3 nm to 70nm. When the average particle diameter is less than 1 nm, the inorganicparticles are embedded in the toner, and their functions may not beeffectively exhibited. When it exceeds 100 nm, they may ununiformlyscratch a surface of an electrostatic latent image bearing member. Asthe external additives, it is possible to use inorganic particles andhydrophobized inorganic particles may be used in combination, and it ispreferable to include at least two types of hydrophobized inorganicparticles having an average particle diameter of primary particlesthereof of 20 nm or less and at least one type of inorganic particleshaving an average particle diameter of 30 nm or greater. Also, theinorganic particles preferably have a BET specific surface area of 20m²/g to 500 m²/g.

An added amount of the external additives is preferably 0.1% by mass to5% by mass, and more preferably 0.3% by mass to 3% by mass.

Resin particles may also be added as an external additive. Examples ofthe resin particles include: polystyrene obtained by soap-free emulsionpolymerization, suspension polymerization or dispersion polymerization;copolymers of methacrylic acid ester or acrylic acid ester;polycondensation system such as silicone, benzoguanamine and nylon; andpolymer particles of a thermosetting resin. By using these resinparticles in combination, charging property of the toner may beenhanced, oppositely charged toner may be reduced, and background smearmay be reduced. An added amount of the resin particles with respect tothe toner is preferably 0.01% by mass to 5% by mass, and more preferably0.1% by mass to 2% by mass.

<<Fluidity Improving Agent>>

When the toner particles are surface treated with the fluidity improvingagent, hydrophobicity of the surface of the toner particles improves,and decrease in fluidity property and charging property may besuppressed even under a high-humidity environment.

Examples of the fluidity improving agent include a silane couplingagent, a silylating agent, a silane coupling agent including afluorinated alkyl group, an organic titanate coupling agent, an aluminumcoupling agent, silicone oil and modified silicone oil.

<<Cleanability Improving Agent>>

When the cleanability improving agent is added to the toner, a developerremaining on a photoconductor or a primary transfer medium aftertransfer may be easily removed.

Examples of the cleanability improving agent include: a metal salt of afatty acid such as stearic acid, including zinc stearate and calciumstearate; and resin particles obtained by soap-free emulsionpolymerization of methyl methacrylate particles or polystyreneparticles. The resin particles preferably have narrow particle sizedistribution and a volume-average particle diameter of 0.01 μm to 1 μm.

<<Magnetic Material>>

The magnetic material is not particularly restricted and may beappropriately selected according to purpose. Examples thereof includeiron powder, magnetite and ferrite. Among these, white magnetic materialis preferable in view of color.

[Weight-Average Molecular Weight]

The weight-average molecular weight of the tetrahydrofuran (THF) solublecontent of the toner is not particularly restricted as long as it is20,000 to 60,000, and it may be appropriately selected according topurpose. It is preferably 30,000 to 50,000, and more preferably 35,000to 45,000. The weight-average molecular weight exceeding 60,000 is notpreferable since the binder resin as a whole having a too high molecularweight degrades fixing property, resulting in low gloss and missingimage after fixing due to external stress. The weight-average molecularweight of less than 20,000 is also not preferable since internalcohesion during toner melting decreases too much even though manyhigh-molecular weight components exist, resulting in hot offset andpaper winding on a fixing member.

[Amount of High-Molecular Weight Component]

The tetrahydrofuran soluble content of the toner is not particularlyrestricted as long as it includes 5.0% or more as a peak area of acomponent having a molecular weight of 100,000 or greater in a molecularweight distribution measured by gel permeation chromatography (GPC), andit may be appropriately selected according to purpose. It includespreferably 7.0% or more, and more preferably 9.0% or more. An upperlimit thereof is not particularly restricted and may be appropriatelyselected according to purpose, and it is preferably 25.0% or less.

By including 5.0% or more the component having a molecular weight of100,000 or greater, fluidity and viscoelasticity of the toner aftermelting is less temperature-dependent, and significant difference in thefluidity and the viscoelasticity of the toner during fixing hardlyoccurs between thin paper in which heat is easily transferred and thickpaper in which heat is not easily transferred. Thus, it is possible in afixing apparatus to fix at a constant temperature and a constant speed.When the content of the component having a molecular weight of 100,000is less than 5.0%, the fluidity and the viscoelasticity of the tonerafter melting varies largely depending on a temperature. Thus, in fixingon thin paper, for example, the toner is excessively deformed, causingincrease of an area of adhesion to a fixing member. As a result, thetoner may not be released well from the fixing member, causing paperwrapping.

Moreover, the tetrahydrofuran soluble content of the toner preferablyincludes 0.5% or more as the peak area of a component having a molecularweight of 250,000 or greater in a molecular weight distribution measuredby gel permeation chromatography (GPC) since it reduces a difference inglossiness between thin paper and thick paper.

In the present invention, a tetrahydrofuran soluble content of a toneras well as a molecular weight distribution and a weight-averagemolecular weight (Mw) of a resin may be measured using a gel permeationchromatography (GPC) measuring apparatus (e.g. HLC-8220GPC, manufacturedby Tosoh Corporation). As a column, TSK-GEL SUPER HZM-H 15 cm intriplicate was used. A resin to be measured is dissolved intetrahydrofuran (THF) (including a stabilizer, manufactured by Wako PureChemical Industries, Ltd.) to form a 0.15-% by mass solution. Thesolution is filtered using a 0.2-μm filter, and a filtrate thereof isused as a sample. By injecting 100 μL of the THF sample solution in themeasuring apparatus, a measurement is taken at a flow rate of 0.35mL/min in an environment having a temperature of 40° C.

The molecular weight is calculated using a calibration curve formed bymonodispersed polystyrene standard samples. As the standard polystyrenesamples, SHOWDEX STANDARD series manufactured by Showa Denko K.K. andtoluene are used. THF solutions of the following three types ofmonodispersed polystyrene standard samples are prepared, andmeasurements are taken with the above conditions, and a calibrationcurve is created with a retention time of peak top as a light scatteringmolecular weight of the monodispersed polystyrene standard samples.

Solution A: S-7450: 2.5 mg; S-678: 2.5 mg; S-46.5: 2.5 mg; S-2.90: 2.5mg; THF: 50 mL

Solution B: S-3730: 2.5 mg; S-257: 2.5 mg; S-19.8: 2.5 mg; S-0.580: 2.5mg; THF: 50 mL

Solution C: S-1470: 2.5 mg; S-112: 2.5 mg; S-6.93: 2.5 mg; toluene: 2.5mg; THF: 50 mL

As a detector, an RI (refractive index) detector is used.

A proportion of the component having a molecular weight of 100,000 orgreater may be calculated from an intersection of the molecular weightof 100,000 with an integral molecular weight distribution curve by theGPC measurement.

A proportion of the component having a molecular weight of 250,000 orgreater may be calculated from an intersection of the molecular weightof 250,000 with an integral molecular weight distribution curve by theGPC measurement.

Examples of a method for obtaining a toner including a binder resinhaving a molecular weight distribution described above include: a methodto use two or more types of resins having different molecular weightdistribution in combination; and a method to use a resin whose molecularweight distribution has been controlled during polymerization.

When two or more types of resins having different molecular weightdistribution are used in combination, at least two types of resinshaving a relatively high molecular weight and a relatively low molecularweight are used. As the resin having a high molecular weight; a resinwhich has a large molecular weight in advance may be used, or ahigh-molecular weight body may be formed by elongating a modified resinincluding an isocyanate group at an end thereof in a process ofmanufacturing the toner. The latter allows the high-molecular weightbody to exist uniformly in the toner. Thus, for a manufacturing methodincluding a step of dissolving a binder resin in an organic medium, thelatter is preferable since dissolution thereof is easier than the resinhaving a high molecular weight in advance.

When the resin whose molecular weight distribution is controlled duringpolymerization is used, as a method for obtaining such a resin, forexample, the molecular weight distribution may be widened by adding asmall amount of monomer having a different number of functional groupsin addition to a bifunctional monomer, provided that a form ofpolymerization is polycondensation, polyaddition or additioncondensation. As the monomer having a different number of functionalgroups, there are tri- or more functional monomer and a mono-functionalmonomer. However, use of the tri- or more functional monomer generates abranched structure, and it may be difficult to form a crystallinestructure in the case of using a resin having crystallinity. By usingthe mono-functional monomer, polymerization reaction is terminated bythe mono-functional monomer. Thereby, in the case of using two or moretypes of resins, a low-molecular weight resin is generated while thepolymerization reaction proceeds partly to form a high-molecular weightcomponent.

Examples of the mono-functional monomer include a monool, amonocarboxylic acid and a monoamine compound.

Examples of the monool include methanol, ethanol, propanol, isopropanol,butanol, sec-butanol, t-butanol, pentanol, hexanol, heptanol, octanol,2-ethylhexanol, nonanol, decanol, undecanol, lauryl alcohol, myristylalcohol, palmityl alcohol, stearyl alcohol, docosanol, eicosanol, phenoland a substitution product thereof, 1-naphtol, 2-naphtol, benzyl alcoholand a substitution product thereof, cyclopentanol, cyclohexanol,adamantanol, and cholesterol and a substitution product thereof.

Examples of the monocarboxylic acid include formic acid, acetic acid,butyric acid, valeric acid, isovaleric acid, caproic acid,2-ethylhexanoic acid, heptanoic acid, caprylic acid, capric acid, lauricacid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleicacid, behenic acid, cerotic acid, montanic acid, triacontanoic acid,benzoic acid and a substitution product thereof, and benzyl acid and asubstitution product thereof.

Examples of the monoamine compound include: an alkyl amine such asmethylamine, dimethylamine, ethylamine, diethylamine, propylamine,dipropylamine, butylamine, dibutylamine, hexylamine, octylamine,2-ethylhexylamine, decylamine, laurylamine, myristyl amine, palmitylamine, stearyl amine and behenyl amine; an amino acid such as glycine,α-alanine, β-alanine, arginine, asparagine, aspartic acid, cysteine,glutamine, glutamic acid, histidine, isoleucine, leucine, lysine,methionine, phenylalanine, proline, serine, threonine, tryptophan,tyrosine and valine; an aromatic amino acid such as aniline,benzylamine, o-anisidine, m-anisidine, p-anisidine, o-toluidine,m-toluidine and p-toluidine.

[Amount of Crystalline Structure [C/(A+C)]]

In a diffraction spectrum of the toner obtained by an x-ray diffractionapparatus, a ratio of (C) integrated intensity of the spectrum derivedfrom a crystalline structure to a sum of the (C) and (A) integratedintensity of the spectrum derived from a non-crystalline structure[C/(A+C)] is not particularly restricted and may be appropriatelyselected according to purpose. It is preferably 0.13 or greater in viewof obtaining both fixing property and heat-resistant storage stability,and it is more preferably 0.20 or greater, further more preferably 0.30or greater, and particularly preferably 0.45 or greater. When the ratio[C/(A+C)] is less than 0.13, it may be difficult to obtain bothlow-temperature fixing property and heat-resistant storage stabilitysince the property as a crystalline resin is reduced. The ratio[C/(A+C)] of within the more preferable range is advantageous inobtaining both low-temperature fixing property and heat-resistantstorage stability.

In addition, a heretofore known toner, which includes a crystallineresin or a wax to an extent of additives, has this ratio of less thanabout 0.10.

The ratio [C/(A+C)] is an index indicating an amount of acrystallization site in a toner (an amount of the crystallization siteserving as a main component of the toner), and it is an area ratio of amain diffraction peak derived from the crystalline structure of thebinder resin to a halo derived from the non-crystalline structure in adiffraction spectrum obtained by an x-ray diffraction measurement.

The x-ray diffraction measurement may be performed using an x-raydiffractometer equipped with a 2-dimensional detector (D8 DISCOVER withGADDS, manufactured by Bruker).

As a capillary for the measurement, a mark tube (Lindemann glass) havinga diameter of 0.70 mm is used. A sample is filled to an upper portion ofthis capillary tube for measurement. Also, tapping is performed when thesample is filled, where the number of tapping is 100.

Detailed measurement conditions are described below.

Tube current: 40 mA

Tube voltage: 40 kV

Goniometer 2θ axis: 20.000°

Goniometer Ω axis: 0.0000°:

Goniometer φ axis: 0.0000°:

Detector distance: 15 cm (wide angle measurement)

Measuring range: 3.2≦2θ(°)≦37.2:

Measurement time: 600 sec

A collimator having a pinhole with a diameter of 1 mm was used for anincident optical system. Obtained 2-dimensional data is integrated witha supplied software (at 3.2° to 37.2° in the x-axis) and converted to a1-dimensional data of a diffraction intensity and 2θ. Based on theobtained x-ray diffraction measurement results, a method for calculatingthe ratio (C)/((C)+(A)) is explained below.

An example of a diffraction spectrum obtained by an x-ray diffractionmeasurement is illustrated in FIG. 1A and FIG. 1B. The horizontal axisrepresents 20, the vertical axis represents the x-ray diffractionintensity, and the both are linear axes. In the x-ray diffractionspectrum A in FIG. 1A, there are main peaks at 2θ=21.3° (P1) and 24.2°(P2), halos (h) are observed in a wide range including these two peaks.Here, the main peaks are derived from a crystalline structure while thehalos are derived from a non-crystalline structure.

These two main peaks and halos are expressed by a Gaussian functions(f_(p1)(2θ), f_(p2)(2θ), f_(h)(2θ) denote main peak P1, main peak P2 andhalos, respectively):f _(p1)(2θ)=a _(p1)exp[−(2θ−b _(p1))²/(2c _(p1) ²)]  (Formula A(1))f _(p2)(2θ)=a _(p2)exp[−(2θ−b _(p2))²/(2c _(p2) ²)]  (Formula A(2))f _(h)(2θ)=a _(h)exp[−(2θ−b _(h))²/(2c _(h) ²)]  (Formula A(3))A sum of these functions:f(2θ)=f _(p1)(2θ)+f _(p2)(2θ)+f _(h)(2θ)  (Formula A(4))is regarded as a fitting function F of the overall x-ray diffractionspectrum A (illustrated in FIG. 1B), with which fitting by a leastsquare method is carried out.

There are 9 fitting variables, namely a_(p1), b_(p1), C_(p1), a_(p2),b_(p2), C_(p2), a_(h), b_(h) and c_(h). As initial values of thesevariables for fitting, peak locations of the x-ray diffraction are setfor b_(p1), b_(p2) and b_(h) (in the example of FIG. 1A, b_(p1)=21.3,b_(p2)=24.2, and b_(h)=22.5), and appropriate values are input for theother variables so that the two main peaks and halos coincide as much aspossible with the x-ray diffraction spectrum. The fitting may be carriedout using the solver of Excel 2003, manufactured by MicrosoftCorporation.

From the integrated areas (S_(p1), S_(p2), S_(h)) of the respectiveGaussian functions f_(p1)(2θ), f_(p2)(2θ) corresponding to the two mainpeaks (P1, P2) and Gaussian function f_(h)(2θ) corresponding to thehalos after fitting, the ratio [C/(A+C)] as an index indicating theamount of the crystallization site may be calculated, assuming(S_(p1)+S_(p2)) is (C) and (S_(h)) is (A).

[Mixed Solution Insoluble Content]

An insoluble content of the toner with respect to a mixed solution oftetrahydrofuran and ethyl acetate (tetrahydrofuran/ethyl acetate=50/50(mass ratio)) is not particularly restricted and may be appropriatelyselected according to purpose. It is preferably 5.0% by mass or greater,and more preferably 10.0% by mass or greater. An upper limit thereof isnot particularly restricted and may be appropriately selected accordingto purpose. It is preferably 25.0% by mass or less, and more preferably20.0% by mass or less. When the insoluble content is less than 5.0% bymass, heat-resistant storage stability may degrade, and offset may occurin fixing, especially in fixing at a high temperature. The insolublecontent of within the more preferable range is advantageous forobtaining both low-temperature fixing property and heat-resistantstorage stability.

Here, the mixed solution of tetrahydrofuran and ethyl acetate(tetrahydrofuran/ethyl acetate=50/50 (mass ratio)) hardly dissolves ahigh-molecular weight component in the toner (having a molecular weightof about 20,000 or greater) and easily dissolves a low-molecular weightcomponent having a molecular weight less than that. Thus, it is possibleto prepare a sample with increased concentration of high-molecularweight resin component by treating the toner using the above mixedsolution.

The insoluble content may be obtained by: adding 0.4 g of toner to 40 gof a mixed solution of tetrahydrofuran (THF) and ethyl acetate (with amixing ratio of 50:50 as a mass basis), shaking it for 20 minutes,precipitating a non-soluble content by centrifuge, removing asupernatant, and vacuum drying the remaining.

[Ratio of Endothermic Quantity [ΔH(H)/ΔH(T)]]

A ratio [ΔH(H)/ΔH(T)] of an endothermic quantity [ΔH(T), (J/g)] in thedifferential scanning calorimetry of the toner and an endothermicquantity [ΔH(H), (J/g)] in the differential scanning calorimetry of theinsoluble content to the mixed solvent of tetrahydrofuran and ethylacetate [tetrahydrofuran/ethyl acetate=50/50 (mass ratio)] is notparticularly restricted and may be appropriately selected according topurpose. It is preferably 0.20 to 1.25.

The endothermic quantity may be measured using a differential scanningcalorimeter (TA-60WS and DSC-60 (manufactured by Shimadzu Corporation)),for example. A sample subjected to the measurement of the maximum peaktemperature of heat of fusion is heated from 20° C. to 150° C. at aheating rate of 10° C./rain, then cooled to 0° C. at a cooling rate of10° C./min, and again heated at a heating rate of 10° C./min, and anendothermic-exothermic change is measured. The heat flow is plottedagainst the temperature, and the endothermic quantity in the secondtemperature increase is evaluated.

The ratio [ΔH(H)/ΔH(T)] indicate a ratio of the crystalline structure inthe high-molecular weight component and the crystalline structure of theentire binder resin.

The high-molecular weight component preferably has a resin structureclose to the entire binder resin, and if the binder resin hascrystallinity, it is preferable that the high-molecular weight componentsimilarly has crystallinity. On the other hand, when the high-molecularweight component has a structure largely different from the other resincomponents, the high-molecular weight component easily undergoes layerseparation to be in a sea-island state, and contribution to improvementsof viscoelasticity and cohesive force to the entire toner may not beexpected.

The ratio [ΔH(H)/ΔH(T)] of within the preferable range is advantageousin terms of uniform charging property since the low-molecular weightcomponent and the high-molecular weight component of the resin in thetoner are more uniformly present, resulting in less variation amongtoner particles.

[Maximum Peak Temperature of Heat of Fusion and Heat of Fusion Quantity]

The maximum peak temperature and the endothermic quantity [ΔH(T), (J/g)]of the heat of fusion in the second temperature increase measured by adifferential scanning calorimeter (DSC) are not particularly restrictedand may be appropriately selected according to purpose. The maximum peaktemperature and the heat of fusion quantity [ΔH(T), (J/g)] in the secondtemperature increase are preferably 50° C. to 70° C. and 30 J/g to 75J/g, respectively.

The maximum peak temperature is not particularly restricted and may beappropriately selected according to purpose. It is more preferably 55°C. to 68° C., and particularly preferably 58° C. to 65° C. When themaximum peak temperature of the heat of fusion of the toner is less than50° C., blocking of the toner is likely to occur in a high temperatureenvironment. When it exceeds 70° C., it becomes difficult to develop lowtemperature fixing property.

The endothermic quantity [ΔH(T), (J/g)] of the toner is not particularlyrestricted and may be appropriately selected according to purpose. It ismore preferably 45 J/g to 70 J/g, and particularly preferably 50 J/g to60 J/g. When the endothermic quantity [ΔH(T), (J/g)] of the toner isless than 30 J/g, the toner has decreased portions with a crystallinestructure and decreased sharp melt property, making it difficult tobalance heat-resistant storage stability and low-temperature fixingproperty. When it exceeds 75 J/g, energy required for melting and fixingthe toner increases, and fixing property may degrade depending on afixing apparatus.

Similarly to the resin, the maximum peak temperature of the heat offusion of the toner may be measured using a differential scanningcalorimeter (TA-60WS and DSC-60 (manufactured by Shimadzu Corporation),for example). First, a sample for measuring the maximum peak temperatureof the heat of fusion is heated from 20° C. to 150° C. at a heating rateof 10° C./min, then cooled to 0° C. at a cooling rate of 10° C./min andthen heated at a heating rate of 10° C., and an endothermic-exothermicchange is measured. The “endothermic-exothermic change” is plottedagainst the “temperature”, and a temperature corresponding to themaximum peak of the heat of fusion is determined as the maximum peaktemperature of the heat of fusion in the second temperature increase.Also, an endothermic quantity of the endothermic peak having the maximumpeak temperature is defined as an endothermic quantity in the secondtemperature increase.

[Storage Modulus G′(70), Storage Modulus G′(160)]

A storage modulus of the toner at 70° C., G′(70) (Pa), is notparticularly restricted and may be appropriately selected according topurpose. It is preferably 1.0×10⁴ Pa to 5.0×10⁵ Pa, more preferably1.0×10⁴ Pa to 1.0×10⁵ Pa and particularly preferably 5.0×10⁴ Pa to1.0×10⁵ Pa. When the storage modulus G′(70) is less than 1.0×10⁴ Pa,blocking phenomenon that fixed images are adhered to each other islikely to occur after continuous output of the fixed images. When itexceeds 5.0×10⁵ Pa, melting property of the toner decreases in a lowtemperature region, and a fixed image tends to have decreasedglossiness.

A storage modulus of the toner at 160° C., G′(160) (Pa), is notparticularly restricted and may be appropriately selected according topurpose. It is preferably 1.0×10³ Pa to 5.0×10⁴ Pa, more preferably1.0×10³ Pa to 1.0×10⁴ Pa and particularly preferably 5.0×10³ Pa to1.0×10⁴ Pa. When the storage modulus G′(160) is less than 1.0×10³ Pa,hot-offset resistance tends to degrade. When it exceeds 5.0×10⁴ Pa, afixed image tends to have decreased glossiness.

Also, it is preferable that the storage modulus, G′(70) (Pa), is 1.0×10⁴to 5.0×10⁵ and that the storage modulus, G′(160) (Pa), is 1.0×10³ to5.0×10⁴. The storage modulus G′(70) and the storage modulus G′(160)within the above ranges suppress peeling images when an image is fixedat a low temperature and offset of a toner to a fixing member when animage is fixed at a high temperature may be suppressed more effectively,and as a result, it is possible to improve resistance to stirringstress.

The dynamic viscoelastic properties of the toner (storage modulus G′ andloss modulus G″) may be measured using a dynamic viscoelasticitymeasuring apparatus (for example, ARES (manufactured by TA Instruments,Inc.)). It is measured under a frequency of 1 Hz. A sample is formedinto pellets having a diameter of 8 mm and a thickness of 1 mm to 2 mm,fixed on a parallel plate having a diameter of 8 mm, which is thenstabilized at 40° C., and heated to 200° C. at a heating rate of 2.0°C./min with a frequency of 1 Hz (6.28 rad/s) and a strain amount of 0.1%(strain amount control mode), and a measurement is taken.

[Content of N Element in THF-Soluble Content of Toner]

A content of N element in a CHN analysis of the THF soluble content ofthe toner is not particularly restricted and may be appropriatelyselected according to purpose. It is preferably 0.3% by mass to 2.0% bymass, more preferably 0.5% by mass to 1.8% by mass, and particularlypreferably 0.7% by mass to 1.6% by mass. When the content of N elementexceeds 2.0% by mass, the toner in a molten state has an excessivelyhigh viscoelasticity. As a result, it is possible that fixing property,glossiness and charging property may degrade. When the content is lessthan 0.3% by mass, aggregation and pollution of members in an imageforming apparatus due to degreased toughness of the toner orhigh-temperature offset due to decreased viscoelasticity of the toner ina molten state may occur.

The content of N element is an amount of N element derived from aurethane bond and a urea bond.

The content of N element in the present invention may be obtained as anaverage value of two measurement values of CHN simultaneous measurementunder conditions of a combustion furnace of 950° C., a reduction furnaceof 550° C., a helium flow rate of 200 mL/min and an oxygen flow rate of25 mL/min to 30 mL/min using VARIO MICRO CUBE (manufactured by ElementarAnalytical). Here, when the content of N element obtained by thismeasurement method is less than 0.5% by mass, a further measurement isconducted using a trace nitrogen analyzer ND-100 (manufactured byMitsubishi Chemical Corporation). An electric furnace (horizontalreactor) has temperatures in a thermal decomposition part of 800° C. andin a catalytic part of 900° C., and with measurement conditions of themain O₂ flow rate of 300 mL/min, Ar flow rate of 400 mL/min, and thesensitivity of Low, quantity is determined using a calibration curvecreated with pyridine standard solutions.

Here, the THF soluble content of the toner may be obtained beforehand byplacing 5 g of toner in a Soxhlet extractor, carrying out extractionusing this for 20 hours with 70 mL of THF and removing THF by heatingunder a reduced pressure.

[Urea Bond]

It is important that a urea bond exist in the THF soluble content of thetoner since effects of improved toughness of the toner and offsetresistance during fixing may be expected even with a small amount of theurea bond.

The presence of the urea bond in the THF soluble content of the tonermay be analyzed using ¹³C-NMR.

Specifically, the analysis is conducted as follows. After 2 g of asample to be analyzed is soaked in 200 mL of a methanol solution ofpotassium hydroxide having a concentration of 0.1 mol/L and left at 50°C. for 24 hours, the solution is removed, the residue is further washedwith ion-exchange water until a pH thereof becomes neutral, and theremaining solid is dried. The sample after drying is added with a mixedsolvent of dimethylacetamide (DMAc) and deuterated dimethyl sulfoxide(DMSO-d6) (having a volume ratio of 9:1) with a concentration of 100mg/0.5 mL. This is dissolved first at 70° C. for 12 hours to 24 hoursand then to 50° C., and ¹³C-NMR measurement is conducted. Here, ameasurement frequency is 125.77 MHz, 1H_(—)60° pulse is 5.5 μs, and areference substance is 0.0 ppm of tetramethylsilane (TMS).

The presence of a urea bond in the sample is confirmed by whether or nota signal is observed in a chemical shift of a signal derived from thecarbonyl carbon of the urea bond site of a polyurea as a preparation.The chemical shift of the carbonyl carbon is generally observed at 150ppm to 160 ppm. As one example of polyurea, a ¹³C-NMR spectrum near acarbonyl carbon of a polyurea as a reaction product of4,4′-diphenylmethane diisocyanate (MDI) and water is illustrated in FIG.2. A signal derived from the carbonyl carbon is observed at 153.27 ppm.

[Urethane Bond]

The THF soluble content of the toner preferably includes a urethanebond. The urethane bond may be confirmed by, other than resin componentmonomer analysis using infrared absorption spectrum or pyrolysis gaschromatogram-mass spectrometry, using ¹³C-NMR similarly to theconfirmation method for the urea bond.

[Volume Resistivity of Toner]

A common logarithmic value of a volume resistivity R [Ω·cm] of the toneris not particularly restricted and may be appropriately selectedaccording to purpose. It is preferably 10.0 to 10.6 since chargeimparted to the toner by frictional electrification is favorablyretained on a surface of the toner in developing and transfer processes.When the crystalline resin includes a urethane/urea bond, it isconsidered that these functional groups are likely to leak the charge.However, in order to enhance mechanical strength of the crystallineresin, it is desirable to bind crystalline portions with thesefunctional groups. Thus, when the common logarithmic value is within thepreferable range, satisfactory developing and transferring propertiesmay be obtained without toner degradation. The common logarithmic valueof less than 10.0 causes the charge to leak on a contact member such ascarrier, charge roller and photoconductor. As a result, a latent imagemay not be closely developed, or non-transferred toner, which cannotmove in a transfer electric field, is likely to remain on thephotoconductor. On the other hand, it is necessary to have a highresistance to some extent in order to maintain the charge. However, whenthe common logarithmic value is higher than 10.6, the crystalline resinof the present invention has a decreased mechanical strength despitefavorable developing and transfer properties. Thus, the tonerdegradation such as aggregation and deformation occurs due to contact orfriction with internal members of the apparatus, and a satisfactoryimage may not be obtained.

Here, electrical resistance depends on abundance of the urethane bondand urea bond. It also depends largely on the crystalline state in theresin, and the resistance may be increased with higher crystallinity.Accordingly, in order to adjust the electrical resistance within theabove range while maintaining the mechanical strength, it is effectiveto increase a size of crystalline portion in the polymer. For example,there are methods such as subjecting the obtained toner to crystalgrowth by heat treatment under appropriate conditions and adjustingproduction conditions such as heating temperature and heating time. Itis also effective that materials which suitable for growing crystals(e.g. fine low-molecular crystalline organic compound, fine inorganicparticles, metal oxides and inorganic salts) are included in the tonerin advance.

[Method for Measuring Volume Resistivity of Toner]

To measure the common logarithmic value Log R of the volume resistivityR [Ω·cm] of the toner, a sample for measurement is produced by molding 3g of the toner into pellets having a diameter of 40 mm and a thicknessof 2 mm (a pressure device BRE-32 manufactured by Maekawa TestingMachine MFG. Co., Ltd.; load of 6 MPa and pressing time of 1 minute).This is set in SE-70 solid-state electrodes (manufactured by AndoElectric Co., Ltd.), and Log R when an alternating current of 1 kHz isapplied between the electrodes is measured using an AC bridge instrumentcomposed of TR-10C dielectric loss measuring instrument, WBG-9oscillator and BDA-9 equilibrium point detector (all manufactured byAndo Electric Co., Ltd.), and thereby Log R of the toner is obtained.

(Method for Manufacturing Toner)

A method for preparing a toner of the present invention is notparticularly restricted and may be appropriately selected according topurpose. Examples thereof include: heretofore known wet granulationmethods such as dissolution suspension method and emulsion aggregationmethod; and a pulverization method. Among these, the dissolutionsuspension method and the emulsion aggregation method, which aremanufacturing methods not involving kneading of a binder resin, arepreferable in view of cutting of molecules due to kneading anddifficulty of uniform kneading of a high-molecular weight resin and alow-molecular weight resin. Moreover, the dissolution suspension methodis particularly preferable in view of uniformity of resins in tonerparticles.

Alternatively, the above toner may be manufactured the particlemanufacturing method described in, for example, JP-B No. 4531076.Specifically, in this particle manufacturing method, materials forforming toner particles are dissolved in carbon dioxide of a liquid orsupercritical state and then the carbon dioxide is removed to obtaintoner particles.

[Dissolution Suspension Method]

A toner is manufactured by the dissolution suspension method as follows.

First, a toner material solution is prepared by dispersing or dissolvingthe above toner materials such as colorant, binder resin and releasingagent in an organic medium. Next, the toner material solution isemulsified in an aqueous medium in the presence of a surfactant andresin particles, and thereby particles are obtained.

—Organic Medium—

The organic solvent preferably volatile having a boiling point less than100° C. since it may be easily removed after formation of toner baseparticles. Examples of the organic solvent includes toluene, xylene,benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane,1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene,dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone,and methyl isobutyl ketone. These may be used alone or in combination oftwo or more. Among these, aromatic solvents such as toluene and xylene,halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane,chloroform and carbon tetrachloride, and ethyl acetate are preferable.An amount of the organic solvent used with respect to 100 parts by massof the toner materials is usually 0 parts by mass to 300 parts by mass,preferably 0 parts by mass to 100 parts by mass, and more preferably 25parts by mass to 70 parts by mass.

—Aqueous Medium—

The aqueous medium may be water alone, or it may further include anorganic solvent such as alcohols (e.g. methanol, isopropyl alcohol andethylene glycol), dimethylformamide, tetrahydrofuran, cellosolves (e.g.methyl cellosolve) and lower ketones (e.g. acetone and methyl ethylketone).

An amount of the aqueous solvent used with respect to 100 parts by massof the toner material solution is usually 50 parts by mass to 2,000parts by mass, and preferably 100 parts by mass to 1,000 parts by mass.When the amount is less than 50 parts by mass, toner particles having apredetermined particle diameter cannot be obtained due to poordispersion state of the toner material liquid. The amount exceeding20,000 parts by mass is not economical.

—Surfactant, Resin Particles—

Further, appropriate addition of the surfactant or the resin particlesas a dispersant is for favorable dispersion of the colorant, the hybridresin and the releasing agent.

The surfactant is not particularly restricted and may be appropriatelyselected according to purpose. Examples thereof include: anionicsurfactants such as alkylbenzene sulfonate, α-olefin sulfonate, andphosphate ester; cationic surfactants of amine salt type includingalkylamine salt, amino alcohol fatty acid derivatives, polyamine fattyacid derivatives and imidazoline, and cationic surfactants of quaternaryammonium salt type including alkyl trimethyl ammonium salts, dialkyldimethyl ammonium salt, alkyl dimethyl benzyl ammonium salts, pyridiniumsalts, alkyl isoquinolinium salts and benzethonium chloride; non-ionicsurfactants such as fatty acid amide derivatives and polyhydric alcoholderivatives; and amphoteric surfactants such as alanine,dodecyldi(aminoethyl)glycine, di(octylaminoethyl)glycine,N-alkyl-N,N-dimethyl ammonium betaine.

Also, use of a surfactant having a fluoroalkyl group such as anionicsurfactant having a fluoroalkyl group and cationic surfactant having afluoroalkyl group is effective even with a very small amount thereof.

Examples of the anionic surfactants having a fluoroalkyl group which maybe favorably used include: fluoroalkyl carboxylic acid having 2 to 10carbon atoms and metal salts thereof, disodiumperfluorooctanesulfonylglutamate, sodium 3-[Ω-fluoroalkyl(C6 toC11)oxy]-1-alkyl(C3 to C4) sulfonate and sodium 3[Ω-fluoroalkanoyl(C6 toC8)-N-ethylamino]-1-propanesulfonate, fluoroalkyl(C11 to C20) carboxylicacid and metal salts thereof, perfluoroalkyl(C7 to C13) carboxylic acidand metal salts thereof, perfluoroalkyl(C4 to C12) sulfonic acid andmetal salts thereof, perfluorooctane sulfonic acid diethanolamide,N-propyl-N-(2-hydroxyethyl)perfluorooctane sulfonamide,perfluoroalkyl(C6 to C10) sulfonamide propyl trimethyl ammonium salt,perfluoroalkyl(C6 to C10)-N-ethylsulfonyl glycine salt andmonoperfluoroalkyl(C6 to C16)ethyl phosphate.

As product names, examples thereof include: SURFLON S-111, S-112, S-113(manufactured by Asahi Glass Co., Ltd.); FLUORAD FC-93, FC-95, FC-98,FC-129 (manufactured by Sumitomo 3M Co., Ltd.); UNIDYNE DS-101, DS-102(manufactured by Daikin Industries, Ltd.); MEGAFACE F-110, F-120, F-113,F-191, F-812, F-833 (manufactured by DIC Corporation); EFTOP EF-102,103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured byTohkem Products Co., Ltd.); and FTERGENT F-100, F150 (manufactured byNeos Corporation).

Also, examples of the cationic surfactant having a fluoroalkyl groupinclude: primary, secondary or tertiary aliphatic amine acid having afluoroalkyl group, aliphatic quaternary ammonium salts such asperfluoroalkyl(C6 to C10)sulfonamide propyltrimethylammonium,benzalkonium salts, benzethonium chloride, pyridinium salts andimidazolinium salts; and as product names, SURFLON S-121 (manufacturedby Asahi Glass Co., Ltd.), FLUORAD FC-135 (manufactured by Sumitomo 3MCo., Ltd.), UNIDYNE DS-202 (manufactured by Daikin Industries, Ltd.),MEGAFACE F-150, F-824 (manufactured by DIC Corporation), EFTOP EF-132(manufactured by Tohkem Products Co., Ltd.), and FTERGENT F-300(manufactured by Neos Corporation).

—Resin Particles—

As the resin particles, any resin may be used as long as it forms anaqueous dispersion, and it may be a thermoplastic resin and athermosetting resin.

Examples of the resin include vinyl resins, polyurethane resins, epoxyresins, polyester resins, polyamide resins, polyimide resins,silicon-based resins, phenolic resins, melamine resins, urea resins,aniline resins, ionomer resins and polycarbonate resins. These may beused alone or in combination of two or more.

Among these, vinyl resins, polyurethane resins, epoxy resins, polyesterresins and combinations thereof are preferable since an aqueousdispersion of fine spherical resin particles may be easily obtained.

The vinyl resins are a polymer that a vinyl monomer is homopolymerizedor copolymerized, and examples thereof include a styrene-(meth)acrylicester copolymer, a styrene-butadiene copolymer, a (meth)acrylicacid-acrylic ester polymer, a styrene-acrylonitrile copolymer, astyrene-maleic anhydride copolymer and a styrene-(meth)acrylic acidcopolymer.

The resin particles have an average particle diameter of preferably 5 nmto 200 nm and more preferably 20 nm to 300 nm. An inorganic compounddispersant such as tricalcium phosphate, calcium carbonate, titaniumoxide, colloidal silica and hydroxyapatite may also be used.

—Dispersant—

As the dispersant that may be used in combination with the resinparticles and the inorganic compound dispersant, a polymeric protectivecolloid may be used for stabilizing dispersed droplets.

Examples of the dispersant include: an acid such as acrylic acid,methacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid,fumaric acid, maleic acid and maleic anhydrite; a (meth)acrylic monomerincluding a hydroxyl group such as β-hydroxyethyl acrylate,β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropylmethacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate,3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropylmethacrylate, diethylene glycol monoacrylate, diethylene glycolmonomethacrylate, glycerin monoacrylate, glycerin monomethacrylate,N-methylol acrylamide and N-methylol methacrylamide; a vinyl alcohol oran ether of a vinyl alcohol such as vinyl methyl ether, vinyl ethylether and vinyl propyl ether; an ester of a vinyl alcohol and a compoundincluding a carboxyl group such as vinyl acetate, vinyl propionate andvinyl butyrate; acrylamide, methacrylamide, diacetone acrylamide and amethylol compound thereof; an acid chloride such as acrylic acidchloride and methacrylic acid chloride; a nitrogen-containing compoundsuch as vinyl pyridine, vinyl pyrrolidone, vinyl imidazole and ethyleneimine, and a homopolymer or a copolymer of those including aheterocyclic ring thereof; polyoxyethylene, polyoxypropylene,polyoxyethylene alkyl amine, polyoxypropylene alkyl amine,polyoxyethylene alkyl amide, polyoxypropylene alkyl amide,polyoxyethylene nonylphenyl ether, polyoxyethylene laurylphenyl ether,polyoxyethylene stearylphynyl ester and polyoxyethylene nonylphenylester; and celluloses such as methyl cellulose, hydroxyethyl celluloseand hydroxypropyl cellulose.

[[Method for Dispersion]]

A method for dispersion is not particularly restricted, and a heretoforeknown equipment such as low-speed shearing equipment, high-speedshearing equipment, friction equipment, high-pressure jet equipment andultrasonic waves may be applied. Among these, the high-speed shearingequipment is preferable in order to have a particle size of thedispersion of 2 μm to 20 μm. When the high-speed sharing dispersionequipment is used, the rotational speed is not particularly restricted,but it is usually 1,000 rpm to 30,000 rpm, and preferably 5,000 rpm to20,000 rpm. A dispersion time is not particularly restricted, but it isusually 0.1 min to 5 min in the case of a batch system. A temperatureduring dispersion is usually 0° C. to 150° C. (under pressurization),and preferably 40° C. to 98° C.

[[Removal of Organic Solvent, Washing, Drying]]

The organic solvent is removed, and then the emulsified dispersion(reaction product) is washed and dried to obtain toner base particles.

In order to remove the organic solvent, the entire system is graduallyheated with laminar stirring, giving a strong stirring in apredetermined temperature region, and is then subject to desolvation.Thereby, toner base particles having a spindle shape may be prepared.When a substance soluble in acid or alkali such as calcium phosphate isused as a dispersion stabilizer, calcium phosphate is removed from thetoner base particles by dissolving calcium phosphate with an acid suchas hydrochloric acid followed by rinsing with water. It may also beremoved by operations such as enzymatic degradation. A chargecontrolling agent is implanted to the obtained toner base particles,then inorganic particles such as silica particles and titanium oxideparticles are adhered as an external additive, and thereby a toner isobtained. Here, implantation of the charge controlling agent andadhesion of the inorganic particles are conducted by a heretofore knownmethod such as using a mixer.

In view of uniform particle diameter, [volume-average particlediameter/number-average particle diameter] of the toner of the presentinvention is preferably 1.0 to 1.4, and more preferably 1.0 to 1.3. Thevolume-average particle diameter of the toner varies depending on anapplication, but in general, it is preferably 0.1 μm to 16 μm. The upperlimit is more preferably 11 μm, and further more preferably 9 μm, andthe lower limit is more preferably 0.5 μm, and more preferably 1 μm.Here, the volume-average particle diameter and the number-averageparticle diameter may be measured simultaneously using MULTISIZER III(manufactured by Beckman Coulter, Inc.).

—Particle Diameter Measurement—

A volume-average particle diameter of colored resin particles ismeasured by a Coulter counter method. Examples of a measurementapparatus include Coulter Counter TA-II, Coulter Multisizer II andCoulter Multisizer III (all manufactured by Beckman Coulter, Inc.). Themeasurement method is descried below.

First, 0.1 mL to 5 mL of a surfactant (preferably alkylbenzenesulfonate) is added as a dispersant to 100 mL to 150 mL of anelectrolyte solution. In this case, the electrolyte solution is an about1-% by mass NaCl aqueous solution prepared using primary sodiumchloride, and ISOTON-II (manufactured by Beckman Coulter, Inc.) may beused, for example. Here, 2 mg to 20 mg of a measurement sample isfurther added. The electrolyte solution in which the sample is suspendedis subject to dispersion treatment for about 1 min to 3 min with anultrasonic disperser. With the measurement apparatus, using a 100-μmaperture as an aperture, the volume and the number of the tonerparticles or toner are measured, and a volume distribution and a numberdistribution are calculated. From the obtained distributions, thevolume-average particle diameter and the number-average particlediameter of the toner may be obtained.

As channels, following 13 channels are used: 2.00 μm to less than 2.52μm; 2.52 μm to less than 3.17 μm; 3.17 μm to less than 4.00 μm; 4.00 μmto less than 5.04 μm; 5.04 μm to less than 6.35 μm; 6.35 μm to less than8.00 μm; 8.00 μm to less than 10.08 μm; 10.08 μm to less than 12.70 μm;12.70 μm to less than 16.00 μm; 16.00 μm to less than 20.20 μm; 20.20 μmto less than 25.40 μm; 25.40 μm to less than 32.00 μm; and 32.00 μm toless than 40.30 μm Intended particles have a particle diameter of 2.00μm to less than 40.30 μm.

[Emulsion Aggregation Method]

As a method for manufacturing a toner using an emulsion aggregationmethod, for example, a toner slurry is obtained by aggregating and fusesa binder resin dispersion with a colorant dispersion and a waxdispersion, which is subject to washing and filtration in accordancewith a heretofore known method. A collected matter is dried, and therebythe toner is isolated.

[Pulverization Method]

A method for manufacturing a toner using the pulverization methodincludes at least, for example, in accordance with a heretofore knowntechnique, a step of mechanically mixing a toner composition consistingof a binder resin, a charge controlling agent of the present inventionand a colorant, a step of melt-kneading, a step of pulverizing, and astep of classifying. In this case, in the step of mechanically mixingand the step of melt-kneading, a toner other than the product to beobtained in the steps of pulverizing or classifying may be reused.

The step of mechanically mixing may be carried out under ordinaryconditions using a mixer having a stirring blade and is not particularlyrestricted. After this step is completed, the mixture is charged in akneader for melt-kneading. As a melt-kneader, a uniaxial or biaxialcontinuous kneader and a batch kneader with a roll mill may be used.Specific examples thereof include: a KTK-model twin-screw extruder (KobeSteel, Ltd.); a TEM-model extruder (manufactured by Toshiba Machine Co.,Ltd.); a twin-screw extruder (manufactured by KCK Co., Ltd.); aPCM-model twin-screw extruder (manufactured by Ikegai Corporation); anda co-kneader (manufactured by Buss). It is necessary to carry outmelt-kneading under a condition that a molecular chain of the binderresin is not cut off. When a melt-kneading temperature is too lowcompared to a softening point of the binder resin, the molecular chainis cut off. When the melt-kneading temperature is too high, dispersionof the charge controlling agent and the colorant of the presentinvention do not proceed. Thus, it is preferable that the melt-kneadingtemperature is determined appropriately in accordance with the softeningtemperature of the resin.

When the step of melt-kneading is completed, the melt-kneaded matter ispulverized. In the step of pulverizing, it is preferable that coarsepulverization is followed by fine pulverization. Examples of such apulverization method include: a method to pulverize by collision with acollision plate in a jet stream; a method to pulverize by collisionamong particles in a jet stream; and a method to pulverize in a narrowgap between a mechanically rotating rotor and a stator. After this stepis completed, the pulverized matter is classified in a jet stream usinga centrifugal force, and a toner having a predetermined particle sizemay be obtained.

(Developer)

A developer of the present invention includes at least a toner of thepresent invention, and it further includes other componentsappropriately selected such as carrier. The developer may be aone-component developer or a two-component developer, but it ispreferably the two-component developer in view of improved lifetime whenit is used for a high-speed printer corresponding to recent improvementin information processing speed.

In the case of the one-component developer using the toner, there islittle variation in the particle size of the toner even when the toneris consumed and supplied repeatedly. Also, there is neither filming ofthe toner to a developing roller as a developer bearing member norfusion of the toner to a layer thickness regulating member such as bladefor thinning the toner. Moreover, favorable and stable developingproperty and images may be obtained after a long-term usage (stirring)of a developing unit. Also, in the case of the two-component developer,there is little variation in the particle size of the toner even whenthe toner is consumed and supplied repeatedly, and favorable and stabledeveloping property may be obtained after a long-term stirring of adeveloping unit.

<Carrier>

The carrier is not particularly restricted and may be appropriatelyselected according to purpose. It preferably includes a core materialand a resin layer (coating layer) which coats the core material.

<<Carrier Core Material>>

The core material is not particularly restricted as long as it includesmagnetic particles. Favorable examples thereof include ferrite,magnetite, iron and nickel. Also, in the case where environmentaladaptability which is promoted significantly in recent years is takeninto consideration, as for the ferrite, it is preferable to usemanganese ferrite, manganese-magnesium ferrite, manganese-strontiumferrite, manganese-magnesium-strontium ferrite and lithium ferriteinstead of conventional copper-zinc ferrite.

<<Coating Layer>>

The coating layer includes at least a binder resin, and it may includeother components such as inorganic particles according to necessity.

—Binder Resin—

The binder resin for forming the coating layer of the carrier is notparticularly restricted and may be appropriately selected according topurpose. Examples thereof include: crosslinking copolymers includingpolyolefins (e.g. polyethylene and polypropylene) and modified productsthereof, styrene, an acrylic resin, acrylonitrile, vinyl acetate, vinylalcohol, vinyl chloride, vinyl carbazole and vinyl ether; siliconeresins including an organosiloxane bond and modified products thereof(e.g. products modified by an alkyd resin, a polyester resin, an epoxyresin, polyurethane and polyimide); polyamide; polyester; polyurethane;polycarbonate; a urea resin; a melamine resin; a benzoguanamine resin;an epoxy resin; an ionomer resin; a polyimide resin; and derivativesthereof. These may be used alone or in combination of two or more. Amongthese, silicone resins are particularly preferable.

The silicone resins are not particularly restricted and may beappropriately selected from generally known silicone resins according topurpose. Examples thereof include straight silicone resins consisting oforganosiloxane bonds and silicone resins modified by alkyd, polyester,epoxy, acrylic or urethane.

Examples of commercially available products of the straight siliconeresins include: KR271, KR272, KR282, KR252, KR255, KR152 (manufacturedby Shin-Etsu Chemical Co., Ltd.); and SR2400, SR2405, SR2406(manufactured by Dow Corning Toray Co., Ltd.). Also, specific examplesof the modified silicone resins include: an epoxy-modified product:ES-1001N; an acrylic-modified silicone: KR-5208; a polyester-modifiedproduct: KR-5203; an alkyd-modified product: KR-206; a urethane-modifiedproduct: KR-305 (manufactured by Shin-Etsu Chemical Co., Ltd.); and anepoxy-modified product: SR2115; and an alkyd-modified product: SR2110(manufactured by Dow Corning Toray Co., Ltd.).

Here, the silicone resins may be used alone, but it may be used incombination with a crosslinking component or a charge controllingcomponent. Examples of the crosslinking component include a silanecoupling agent. Examples of the silane coupling agent includemethyltrimethoxysilane, methyltriethoxysilane, octyltrimethoxysilane andaminosilane coupling agent.

—Fine Particles—

Fine particles may be included in the coating layer according tonecessity. The fine particles are not particularly restricted and may beappropriately selected from heretofore known materials according topurpose. Examples thereof include: inorganic fine particles such asmetal powder, tin oxide, zinc oxide, silica, titanium oxide, alumina,potassium titanate, barium titanate and aluminum borate; an electricallyconductive polymer such as polyaniline, polyacetylene,polyparaphenylene, poly(para-phenylene sulfide), polypyrrole andparylene; and organic fine particles such as carbon black. These may beused in combination of two or more.

In addition, a surface of the fine particles may be subject to anelectrically conductive treatment. As the electrically conductivetreatment, for example, the surface of the fine particles are coatedwith aluminum, zinc, copper, nickel, silver, alloys thereof, zinc oxide,titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide,indium oxide doped with tin, and tin oxide and zirconium oxide dopedwith antimony in the form of solid solution or fusion. Among these, amethod of electrically conductive treatment with tin oxide, indium oxideor indium oxide doped with tin is preferable.

A content of the coating layer in the carrier is preferably 5% by massor greater, and more preferably 5% by mass to 10% by mass.

A thickness of the coating layer is preferably 0.1 μm to 5 μm, and morepreferably 0.3 μm to 2 μm.

Here, the thickness of the coating layer may be calculated, for example,from an average value of film thickness values obtained fromobservations using a transmission electron microscope (TEM) or ascanning transmission electron microscope (STEM) of 50 or more carriercross sections prepared by FIB (focused ion beam).

[Method for Forming Carrier Coating Layer]

A method for forming a coating layer on a carrier is not particularlyrestricted, and heretofore known methods for forming a coating layer maybe used. Examples thereof include a method that a coating layer solutionin which the materials described above including the binder resin and abinder resin precursor are dissolved is applied on a surface of a corematerial by a spraying method or a dipping method. It is preferable topromote a polymerization reaction of the binder resin or the binderresin precursor by heating the carrier on which the coating layersolution has been applied and a coating layer is formed on the surfacethereof. The heating treatment may be carried out continuously in acoating apparatus after forming the coating layer, or alternatively, itmay be carried out by another heating means such as ordinary electricfurnace and firing kiln after forming the coating layer.

A temperature of the heating treatment cannot be determinedunconditionally because it varies depending on the constitutionalmaterials used in the coating layer. Nonetheless, it is preferably 120°C. to 350° C., and it is particularly preferably below the decompositiontemperature of the materials constituting the coating layer. Here, thedecomposition temperature of the materials constituting the coatinglayer preferably has an upper limit of around 220° C. A duration of theheating treatment is preferably 5 min to 120 min.

[Physical Properties of Carrier]

The carrier preferably has a volume-average particle diameter of 10 μmto 100 μm and more preferably 20 μm to 65 μm.

The volume-average particle diameter of the carrier of less than 10 μmis not preferable because carrier adhesion may occur due to reduceduniformity of the core material particles. The volume-average particlediameter exceeding 100 μm is not preferable since a fine image is notobtained due to poor reproducibility of image details.

A method for measuring the volume-average particle diameter is notparticularly restricted as long as it is a device that can measure aparticle size distribution. For example, it may be measured using aMICROTRAC particle size distribution analyzer Model HRA9320-X100(manufactured by Nikkiso Co., Ltd.).

The carrier has a volume resistivity of preferably 9 [log(Ω·cm)] to 16[log(Ω·cm)], and more preferably 10 [log(Ω·cm)] to 14 [log(Ω·cm)].

The volume resistivity of less than 9 [log(Ω·cm)] is not preferablesince it causes carrier adhesion in a non-image region. The volumeresistivity exceeding 16 [log(Ω·cm)] is not preferable since a so-callededge effect that image density at an edge is enhanced becomessignificant. The volume resistivity may be adjusted freely within theabove range by adjusting a thickness of the coating layer and thecontent of the electrically conductive particles of the carrieraccording to necessity.

The volume resistivity may be measured as follows. First, the carrier isfilled in a cell consisting of a fluorine resin container which housesan electrode 1a and an electrode 1b having an inter-electrode distanceof 0.2 cm and a surface area of 2.5 cm×4 cm, which is tapped with thefollowing tapping conditions: drop height of 1 cm, tapping speed of 30times/min, and the number of tapping of 10. Next, a DC voltage of 1,000V is applied between the electrodes, and a resistance value r [Ω] after30 sec is measured using a high resistance meter 4329A (HIGHRESISTANCEMETER, manufactured by Yokogawa Hewlett-Packard Ltd.). The volumeresistivity R [log(Ω·cm)] may be calculated according to Formula (3)below:R=Log [r×(2.5 cm×4 cm)/0.2 cm]  (3)

When the developer is a two-component developer, as a mixing ratio of atoner and a carrier in the two-component developer, a mass ratio of thetoner with respect to the carrier is preferably 2.0% by mass to 12.0% bymass, and more preferably 2.5% by mass to 10.0% by mass.

(Image Forming Method and Image Forming Apparatus)

An image forming method of the present invention includes at least anelectrostatic latent image forming step and a developing step, and itfurther includes other steps appropriately selected according tonecessity such as transferring step, fixing step, neutralizing step,cleaning step, recycling step and controlling step.

An image forming apparatus used in the present invention includes atleast an electrostatic latent image bearing member, an electrostaticlatent image forming unit and a developing unit, and it further includesother units appropriately selected according to necessity such astransfer unit, fixing unit, neutralizing unit, cleaning unit, recyclingunit and control unit.

<Electrostatic Latent Image Forming Step and Electrostatic Latent ImageForming Unit>

The electrostatic latent image forming step is a step of forming alatent image on the electrostatic latent image bearing member.

As the electrostatic latent image bearing member (also referred to as“electrophotographic photoconductor” or “photoconductor”), a material,shape, structure and size thereof are not particularly restricted andmay be appropriately selected from those heretofore known. As the shape,a drum shape is preferable. Examples of the material include aninorganic photoconductor of amorphous silicon or selenium and an organicphotoconductor (OPC) of polysilane or phthalopolymethine. Among these,amorphous silicon is preferable.

The electrostatic latent image may be formed by uniformly charging asurface of the electrostatic latent image bearing member followed byimagewise exposure, which may be carried out by the electrostatic latentimage forming unit.

For example, the electrostatic latent image forming unit includes atleast a charger which uniformly charges the surface of the electrostaticlatent image bearing member and an exposure device which exposesimagewise the surface of the electrostatic latent image bearing member.

The charging may be carried out by applying a voltage to the surface ofthe electrostatic latent image bearing member using the charger.

The charger is not particularly restricted and may be appropriatelyselected according to purpose. Examples thereof include: contact chargerheretofore known per se equipped with electrically conductive orsemi-conductive roller, brush, film or rubber blade; and a non-contactcharger which makes use of corona discharge of corotron or scorotron.

It is preferable that the charger is disposed in contact or non-contactwith the electrostatic latent image bearing member and appliessuperimposed DC and AC voltages, thereby charging the surface of theelectrostatic latent image bearing member.

It is also preferable that the charger is a charging roller disposedclosely to the electrostatic latent image bearing member via a gap tapein a non-contact manner and applies superimposed DC and AC voltages,thereby charging the surface of the electrostatic latent image bearingmember.

The exposure may be carried out by exposing imagewise the surface of theelectrostatic latent image bearing member using the exposure device.

The exposure device is not particularly restricted as long as it canexpose imagewise an image to be formed on the surface of theelectrostatic latent image bearing member charged by the charger, and itmay be selected appropriately according to purpose. Examples thereofinclude various exposure devices such as copying optical system, rodlens array system, laser optical system and liquid-crystal shutteroptical system.

Here, in the present invention, a back light system which exposesimagewise from a back side of the electrostatic latent image bearingmember.

<Developing Step and Developing Unit>

The developing step is a step of developing the electrostatic latentimage using the toner of the present invention to form a visible image.

The developing unit is a unit equipped with a toner, which develops theelectrostatic latent image to form the visible image, and the toner isthe toner of the present invention.

The visible image may be formed by developing the electrostatic latentimage using the developer of the present invention, which may beconducted with the developing unit.

The developing unit is not particularly restricted as long as it maydevelop using the developer of the present invention, and it may beappropriately selected from heretofore known units according to purpose.The developing unit preferably contains the developer of the presentinvention and includes at least a developing device which may providethe developer to the electrostatic latent image in a contact ornon-contact manner. The developer equipped with a container containingthe developer is more preferable.

The developing device may be a single-color developing device or amulti-color developing device. For example, the developing devicefavorably includes a stirrer which charges the developer by frictionstir and a rotatable magnet roller.

In the developing unit, the toner and the carrier are mixed and stirred.The toner is charged due to friction and maintained in a state ofstanding spikes on a surface of the rotating magnet roller, and amagnetic brush is formed. Since the magnetic brush is disposed near theelectrostatic latent image bearing member (photoconductor), a part ofthe toner which constitutes the magnetic brush formed on the surface ofthe magnet roller moves to the surface of the electrostatic latent imagebearing member (photoconductor) by an electrical attraction force. As aresult, the electrostatic latent image is developed by the toner, and avisible image of the toner is formed on the surface of the electrostaticlatent image bearing member (photoconductor).

The developer contained in the developing device is the developer of thepresent invention.

<Transfer Step and Transfer Unit>

The transfer step is a step of transferring the visible image on arecording medium. A preferable aspect uses an intermediate transfermember and includes a primary transfer that the visible image istransferred on the intermediate transfer member followed by a secondarytransfer that the visible image is transferred on the recording medium.A more preferable aspect uses a toner of two or more colors or afull-color toner as the toner and includes a primary transfer that thevisible image is transferred on the intermediate transfer member to forma composite transfer image and a secondary transfer that the compositetransfer image is transferred on the recording medium.

The transfer may be carried out by transferring the visible image usingthe transfer unit. As the transfer unit, an aspect including a primarytransfer unit which transfers the visible image on the intermediatetransfer member to form the composite transfer image and a secondarytransfer unit which transfers the composite transfer image on therecording medium is preferable.

Here, the intermediate transfer member is not particularly restrictedand may be appropriately selected according to purpose. A favorableexample includes a transfer belt.

The transfer unit (the primary transfer unit and the secondary transferunit) preferably includes at least a transfer device which peels off andcharges the visible image formed on the electrostatic latent imagebearing member (photoconductor) to the side of the recording medium.There may be one transfer unit, or there may be two or more transferunits.

Examples of the transfer device include a corona transfer device bycorona discharge, a transfer belt, a transfer roller, a pressuretransfer roller and an adhesive transfer device.

Here, the recording medium is not particularly restricted and may beappropriately selected from heretofore known recording media (recordingpaper).

<Fixing Step and Fixing Unit>

The fixing step is a step of fixing the visible image transferred to therecording medium using a fixing apparatus. It may be carried each timethe developer of a respective color is transferred on the recordingmedium, or it may be carried out once at the same time when thedevelopers of respective colors are laminated.

The fixing apparatus is not particularly restricted and may beappropriately selected according to purpose, but a heretofore knownheating and pressurizing unit is preferable. Examples of the heating andpressurizing unit include a combination of a heat roller and a pressureroller and a combination of a heat roller, a pressure roller and anendless belt.

The fixing apparatus preferably includes a heating body equipped with aheating element, a film which is in contact with the heating member anda pressure member which is pressed against the heating body via the filmand passes the recording medium on which a non-fixed image is formedbetween the film and the pressure member to fix by heating. Usually, theheating in the heating and pressurizing unit is preferably at 80° C. to200° C.

Here, in the present invention, a heretofore known optical fixing devicemay be used according to purpose with or in place of the fixing step andthe fixing unit, for example.

The neutralizing step is a step to neutralize the electrostatic imagebearing member by applying a neutralizing bias, and it may be preferablycarried out by a neutralizing unit.

The neutralizing unit is not particularly restricted as long as it canapply the neutralizing bias on the electrostatic image bearing member,and it may be appropriately selected from heretofore known neutralizingdevices. Favorable examples include a neutralizing lamp.

The cleaning step is a step of removing the toner remaining on theelectrostatic image bearing member, and it may be preferably carried outby a cleaning unit.

The cleaning unit is not particularly restricted as long as it canremove the toner on the electrostatic image bearing member, and it maybe appropriately selected from heretofore known cleaners. Favorableexamples thereof include a magnetic brush cleaner, an electrostaticbrush cleaner, a magnetic roller cleaner, a blade cleaner, a brushcleaner and a web cleaner.

The recycling step is a step of recycling the toner removed in thecleaning step to the developing unit, and it may be preferably carriedout by a recycling unit. The recycling unit is not particularlyrestricted, and heretofore known conveying units may be used.

The controlling step is a step of controlling the above steps, and eachstep may be favorably carried out by the controlling unit.

The controlling unit is not particularly restricted as long as it cancontrol the movement of each unit, and it may be appropriately selectedaccording to purpose. Examples thereof include devices such as sequencerand computer.

FIG. 4 illustrates one example of an image forming apparatus used in thepresent invention. An image forming apparatus 100A includes aphotoconductor drum 10, a charge roller 20, an exposure apparatus (notshown), a developing apparatus 40, an intermediate transfer belt 50, acleaning apparatus 60 including a cleaning blade and a neutralizing lamp70.

The intermediate transfer belt 50 is an endless belt stretched by threerollers 51 disposed inside thereof, and it moves in a direction of anarrow in the figure. A part of the three rollers 51 also functions as atransfer bias roller which may apply a transfer bias (primary transferbias) on the intermediate transfer belt 50. Also, a cleaning apparatus90 including a cleaning blade is disposed near the intermediate transferbelt 50. Further, a transfer roller 80 which can apply a transfer bias(secondary transfer bias) for transferring a toner image on transferpaper 95 is disposed facing the intermediate transfer belt 50. Inaddition, in a periphery of the intermediate transfer belt 50, a coronacharging apparatus 58 for applying a charge to the toner imagetransferred on the intermediate transfer belt 50 is disposed between acontact portion of the photoconductor drum 10 with the intermediatetransfer belt 50 and a contact portion of the intermediate transfer belt50 with the transfer paper 95 with respect to a rotational direction ofthe intermediate transfer belt 50.

The developing apparatus 40 is configured with: a developing belt 41;and a black developing unit 45K, a yellow developing unit 45Y, a magentadeveloping unit 45M and a cyan developing unit 45C attached around thedeveloping belt 41. Here, the developing unit 45 of a respective coloris equipped with a developer container 42, a developer supply roller 43and a developing roller 44. Also, the developing belt 41 is an endlessbelt stretched by a plurality of belt rollers and moved in a directionof an arrow in the figure. Moreover, a part of the developing belt 41 isin contact with the photoconductor drum 10.

Next, a method for forming an image using the image forming apparatus100A is explained. First, using the charge roller 20, a surface of thephotoconductor drum 10 is uniformly charged, and then using the exposureapparatus (not shown), an exposure light L is exposed on thephotoconductor drum 10 to form an electrostatic latent image. Next, theelectrostatic latent image formed on the photoconductor drum 10 isdeveloped with a toner supplied from the developing apparatus 40 to forma toner image. Further, the toner image formed on the photoconductordrum 10 is transferred (primary transfer) on the intermediate transferbelt 50 by a transfer bias applied from the roller 51 and thentransferred (secondary transfer) to transfer paper 95 by a transfer biasapplied from the transfer roller 80. Meanwhile, after the toner image istransferred to the intermediate transfer belt 50, the toner remaining ona surface of the photoconductor drum 10 is removed by the cleaningapparatus 60, and the photoconductor drum 10 is neutralized by theneutralizing lamp 70.

FIG. 5 is a second example of an image forming apparatus used in thepresent invention. An image forming apparatus 100B has the sameconfiguration as the image forming apparatus 100A except that thedeveloping belt 41 is not provided and that, around the photoconductordrum 10, the black developing unit 45K, the yellow developing unit 45Y,the magenta developing unit 45M and the cyan developing unit 45C aredisposed to face directly to the photoconductor drum 10.

FIG. 6 illustrates a third example of an image forming apparatus used inthe present invention. An image forming apparatus 100C is a tandem-typecolor image forming apparatus, including a copying apparatus main body150, a sheet feeding table 200, a scanner 300 and an automatic documentfeeder (ADF) 400.

An intermediate transfer belt 50 disposed at a central part of thecopying apparatus main body 150 is an endless belt stretched by threerollers 14, 15 and 16 and moves in a direction of an arrow in thefigure. Near the roller 15, a cleaning apparatus 17 including a cleaningblade is disposed to remove a toner remaining on the intermediatetransfer belt 50 after a toner image is transferred to recording paper.Yellow, cyan, magenta and black image forming units 120Y, 120C, 120M and120K are arranged in parallel facing the intermediate transfer belt 50stretched by the rollers 14 and 15 and along a conveying direction.Also, an exposure apparatus 21 is disposed near the image forming units120. Further, a secondary transfer belt 24 is disposed on a side of theintermediate transfer belt 50 opposite to the side of the image formingunits 120. Here, the secondary transfer belt 24 is an endless beltstretched by a pair of rollers 23, and the recording paper conveyed onthe secondary transfer belt and the intermediate transfer belt 50 maycontact between the rollers 16 and 23. In addition, near the secondarytransfer belt 24, a fixing apparatus 25 equipped with a fixing belt 26as an endless belt stretched by a pair of rollers and a pressure roller27 pressed by the fixing belt 26 is disposed. Here, a sheet invertingdevice 28 is located near the secondary transfer belt 24 and the fixingapparatus 25 for inverting the recording paper in the case of formingimages on both sides of the recording paper.

Next, a method for forming a full-color image using the image formingapparatus 100C is explained. First, a color document is set on adocument table 130 of the automatic document feeder (ADF) 400.Alternatively, the automatic document feeder 400 is opened, the colordocument is set on a contact glass 32 of the scanner 300, and theautomatic document feeder 400 is closed. A start button (not shown) ispressed. The scanner 300 activates after the document is conveyed andtransferred to the contact glass 32 in the case the document has beenset on the automatic document feeder 400, or right away in the case thedocument has been set on the contact glass 32, and a first travellingbody 33 equipped with a light source and a second travelling body 34equipped with a mirror travel. At this time, a light irradiated from thefirst travelling body 33 is reflected from a surface of the document,and the reflected light is reflected by the second travelling body 34,which is received by a reading sensor 36 through an imaging lens 35. Thedocument is read thereby, and black, yellow, magenta and cyan imageinformation may be obtained.

The image information of the respective colors is transmitted to theimage forming unit 120 of the respective colors, and a toner image ofthe respective colors is formed. As illustrated in FIG. 7, each of theimage forming units 120 of the respective colors includes: aphotoconductor drum 10; a charge roller 160 which uniformly charges thephotoconductor drum 10; an exposure apparatus which exposes an exposurelight L on the photoconductor drum 10 to form an electrostatic latentimage of the respective colors; a developing apparatus 61 which developsthe electrostatic latent image with a developer of the respective colorsto form a toner image of the respective colors; a transfer roller 62 fortransferring the toner image to an intermediate belt 50; a cleaningapparatus 63 including a cleaning blade; and a neutralizing lamp 64.

The toner image of the respective colors formed in the image formingunit 120 of the respective colors is sequentially transferred (primarytransfer) and superimposed on the intermediate transfer member 50 whichis stretched and moved by the rollers 14, 15 and 16, and a compositetoner image is formed.

Meanwhile, in the sheet feeding table 200, one of sheet feeding rollers142 is selectively rotated to feed recording paper from one of the paperfeed cassettes 144 equipped in multiple stages in a paper bank 143. Therecording paper is separated one by one by a separation roller 145 andsent to a sheet feeding path 146. Each recording paper is conveyed by aconveying roller 147 and guided to a sheet feeding path 148, and itstops by striking a resist roller 49. Alternatively, a sheet feedingroller is rotated to feed recording paper on a manual feed tray 54. Therecording paper is separated one by one by a separation roller 52 andguided to a manual sheet feeding path 53, and it stops by striking theresist roller 49. Here, the resist roller 49 is generally used whilegrounded, but it may also be used in a state that a bias is applied forremoving paper dust on the recording paper. Next, by rotating the resistroller 49 in accordance with the timing of the composite toner imageformed on the intermediate transfer belt 50, the recording paper is fedbetween the intermediate transfer belt 50 and a secondary transfer belt24. Thereby, the composite toner image is transferred (secondarytransfer) on the recording paper. Here, the toner remaining on theintermediate transfer belt 50 after transferring the composite tonerimage is removed by the cleaning apparatus 17.

The recording paper on which the composite toner image is transferred isconveyed by the secondary transfer belt 24, and then the composite imageis fixed by the fixing apparatus 25. Next, the conveying path isswitched by a switching claw 55, and the recording paper is dischargedonto a paper discharge tray 57 by a discharge roller 56. Alternatively,the conveying path is switched by the switching claw 55, and therecording paper is inverted by an inverting device 28. After an image isformed similarly on the rear surface as well, the recording paper isdischarged onto the paper discharge tray 57 by the discharge roller 56.

In an image forming apparatus of the present invention, a high-gloss andhigh-quality image may be provided for a long period of time by using atoner of the present invention.

EXAMPLES

The present invention will next be described in more detail by way ofExamples. Here, it is easy for persons skilled in the art toappropriately modify/adapt Examples of the present invention so as tocreate other embodiments; it should be noted that the present inventionencompasses such modification/adaption, and the following describespreferred embodiments of the present invention and is not intended tolimit the present invention thereto.

In Examples, the unit “part(s)” is “part(s) by mass.”

(Production of Resins)

First, Production Examples of resins used in Examples and ComparativeExamples will next be described.

[Synthesis of Crystalline Polyester Unit 1]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 249 parts of 1,6-hexanediol,394 parts of sebacic acid and 0.8 parts of dibutyltin oxide, and themixture was allowed to react under normal pressure at 180° C. for 6hours.

Next, the reaction mixture was allowed to react at a reduced pressure of10 mmHg to 15 mmHg for 4 hours, to thereby synthesize [crystallinepolyester unit 1].

The obtained [crystalline polyester unit 1] was found to have a numberaverage molecular weight of 4,000, a weight average molecular weight of9,100 and a melting point of 66° C.

[Synthesis of Crystalline Polyester Unit 2]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 369 parts of 1,10-decanediol,289 parts of adipic acid and 0.8 parts of dibutyltin oxide, and themixture was allowed to react under normal pressure at 180° C. for 6hours.

Next, the reaction mixture was allowed to react at a reduced pressure of10 mmHg to 15 mmHg for 4 hours, to thereby synthesize [crystallinepolyester unit 2].

The obtained [crystalline polyester unit 2] was found to have a numberaverage molecular weight of 4,900, a weight average molecular weight of10,200 and a melting point of 65° C.

[Synthesis of Crystalline Polyester Unit 3]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 230 parts of 1,6-hexanediol,23 parts of 1,4-butanediol, 390 parts of sebacic acid and 0.8 parts ofdibutyltin oxide, and the mixture was allowed to react under normalpressure at 180° C. for 6 hours.

Next, the reaction mixture was allowed to react at a reduced pressure of10 mmHg to 15 mmHg for 4 hours, to thereby synthesize [crystallinepolyester unit 3].

The obtained [crystalline polyester unit 3] was found to have a numberaverage molecular weight of 2,500, a weight average molecular weight of7,600 and a melting point of 57° C.

[Synthesis of Crystalline Polyester Unit 4]

A reaction container equipped with a condenser; a stirrer and anitrogen-introducing tube was charged with 316 parts of 1,10-decanediol,19 parts of 1-docosanol, 271 parts of adipic acid and 0.8 parts ofdibutyltin oxide, and the mixture was allowed to react under normalpressure at 180° C. for 6 hours.

Next, the reaction mixture was allowed to react at a reduced pressure of10 mmHg to 15 mmHg for 4 hours, to thereby synthesize [crystallinepolyester unit 4].

The obtained [crystalline polyester unit 4] was found to have a numberaverage molecular weight of 4,900, a weight average molecular weight of24,200 and a melting point of 63° C.

[Synthesis of Polyurethane Prepolymer 1]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 235 parts of bisphenol Apropylene oxide 2 mole adduct, 10 parts of propylene glycol, 254 partsof 4,4′-diphenylmethane diisocyanate and 600 parts of ethyl acetate, andthe mixture was allowed to react under normal pressure at 80° C. for 3hours to thereby synthesize [polyurethane prepolymer 1].

The obtained [polyurethane prepolymer 1] was found to have a numberaverage molecular weight of 2,600 and a weight average molecular weightof 5,600.

[Synthesis of Polyurethane Prepolymer 2]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 234 parts of bisphenol Apropylene oxide 2 mole adduct, 7 parts of propylene glycol, 2 parts ofion exchange water, 265 parts of 4,4′-diphenylmethane diisocyanate and600 parts of ethyl acetate, and the mixture was allowed to react undernormal pressure at 80° C. for 3 hours to thereby synthesize[polyurethane prepolymer 2].

The obtained [polyurethane prepolymer 2] was found to have a numberaverage molecular weight of 2,900 and a weight average molecular weightof 6,500.

The [polyurethane prepolymer 2] has a urea bond.

[Synthesis of Polyurethane Prepolymer 3]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 80 parts of bisphenol Aethylene oxide 2 mole adduct, 175 parts of bisphenol A propylene oxide 2mole adduct, 11 parts of propylene glycol, 248 parts of isophoronediisocyanate and 600 parts of methyl ethyl ketone, and the mixture wasallowed to react under normal pressure at 80° C. for 3 hours to therebysynthesize [polyurethane prepolymer 3].

The obtained [polyurethane prepolymer 3] was found to have a numberaverage molecular weight of 2,700 and a weight average molecular weightof 5,900.

[Synthesis of Resin a-1]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 430 parts of the [crystallinepolyester unit 1], 176 parts of the [polyurethane prepolymer 1] and 400parts of ethyl acetate, and the mixture was allowed to react undernormal pressure at 80° C. for 5 hours. Thereafter, the solvent wasremoved to obtain [resin a-1] composed of the crystalline polyester unitand the polyurethane prepolymer unit.

The obtained [resin a-1] was found to have a number average molecularweight of 10,100, a weight average molecular weight of 31,000, anitrogen atom concentration of 1.7% by mass and a melting point of 65°C.

[Synthesis of Resin a-2]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 427 parts of the [crystallinepolyester unit 2], 15 parts of 4,4′-diphenylmethane diisocyanate and 420parts of methyl ethyl ketone, and the mixture was allowed to react undernormal pressure at 80° C. for 5 hours. Thereafter, the solvent wasremoved to obtain [resin a-2] where the crystalline polyester units arelinked together by 4,4′-diphenylmethane diisocyanate with the linkingmoiety containing a urethane bond.

The obtained [resin a-2] was found to have a number average molecularweight of 11,300, a weight average molecular weight of 33,000, anitrogen atom concentration of 0.4% by mass and a melting point of 66°C.

[Synthesis of Resin a-3]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 352 parts of the [crystallinepolyester unit 3], 180 parts of the [polyurethane prepolymer 1] and 420parts of ethyl acetate, and the mixture was allowed to react undernormal pressure at 80° C. for 5 hours. Thereafter, the solvent wasremoved to obtain [resin a-3] composed of the crystalline polyester unitand the polyurethane prepolymer unit.

The obtained [resin a-3] was found to have a number average molecularweight of 7,400, a weight average molecular weight of 16,000, a nitrogenatom concentration of 2.0% by mass and a melting point of 56° C.

[Synthesis of Resin a-4]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 242 parts of 1,6-hexanediol,14 parts of 1-docosanol, 33 parts of adipic acid, 374 parts of sebacicacid and 0.8 parts of dibutyltin oxide, and the mixture was allowed toreact under normal pressure at 180° C. for 7 hours.

Next, the reaction mixture was allowed to react at a reduced pressure of10 mmHg to 15 mmHg for 5 hours, to thereby synthesize [resin a-4]composed only of the crystalline polyester unit.

The obtained [resin a-4] was found to have a number average molecularweight of 5,700, a weight average molecular weight of 42,100, a nitrogenatom concentration of less than 0.1% by mass and a melting point of 62°C.

[Synthesis of Resin a-5]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 480 parts of the [crystallinepolyester unit 4], 59 parts of the [polyurethane prepolymer 3] and 531parts of ethyl acetate, and the mixture was allowed to react undernormal pressure at 80° C. for 5 hours. Thereafter, the solvent wasremoved to obtain [resin a-5] composed of the crystalline polyester unitand the polyurethane prepolymer unit.

The obtained [resin a-5] was found to have a number average molecularweight of 5,600, a weight average molecular weight of 40,600, a nitrogenatom concentration of 0.6% by mass and a melting point of 63° C.

[Synthesis of Resin a-6]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 480 parts of the [crystallinepolyester unit 4], 61 parts of the [polyurethane prepolymer 2] and 540parts of ethyl acetate, and the mixture was allowed to react undernormal pressure at 80° C. for 5 hours. Thereafter, the solvent wasremoved to obtain [resin a-6] composed of the crystalline polyester unitand the polyurethane prepolymer unit.

The obtained [resin a-6] was found to have a number average molecularweight of 5,900, a weight average molecular weight of 41,100, a nitrogenatom concentration of 0.6% by mass and a melting point of 63° C.

[Synthesis of Resin b-1]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 389 parts of the [crystallinepolyester unit 1], 45 parts of 4,4′-diphenylmethane diisocyanate and 434parts of ethyl acetate, and the mixture was allowed to react undernormal pressure at 80° C. for 5 hours to thereby obtain [resin b-1]which is a polyester prepolymer.

The [resin b-1] contained a solvent and the solid content of the resinwas 50% by mass.

[Synthesis of Resin b-2]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 682 parts of bisphenol Aethylene oxide 2 mole adduct, 81 parts of bisphenol A propylene oxide 2mole adduct, 283 parts of terephthalic acid, 22 parts of trimelliticanhydride and 2 parts of dibutyltin oxide, and the mixture was allowedto react under normal pressure at 230° C. for 8 hours. The reactionmixture was further allowed to react at a reduced pressure of 10 mmHg to15 mmHg for 5 hours to thereby obtain [intermediate polyester 1]. The[intermediate polyester 1] was found to have a number average molecularweight of 2,100, a weight average molecular weight of 9,500, a Tg of 55°C., an acid value of 0.5 and a hydroxyl value of 49.

Next, a reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 411 parts of the[intermediate polyester 1], 89 parts of isophorone diisocyanate and 500parts of ethyl acetate, and the mixture was allowed to react at 100° C.for 5 hours to thereby obtain [resin b-2] which is a polyesterprepolymer.

The [resin b-2] contained the solvent and the solid content of the resinwas 50% by mass.

[Preparation of Colorant Dispersion Liquid]

A beaker was charged with 20 parts of copper phthalocyanine, 4 parts ofa colorant disperser (SOLSPERSE 28000, product of Lubrizol Co.) and 76parts of ethyl acetate, and the mixture was stirred so that thecomponents were homogeneously dispersed. Thereafter, the copperphthalocyanine was finely dispersed with a beads mill to thereby obtain[colorant dispersion liquid 1]. The [colorant dispersion liquid 1] wasmeasured for volume average particle diameter using particle diametermeasuring device LA-920 (product of HORIBA CO. LTD.) and was found tohave a volume average particle diameter of 0.3 μm.

[Preparation of Releasing Agent Dispersion Liquid 1]

A reaction container equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 15 parts of [sunflower wax](ECOSOLE, product of NIPPON SEIRO CO. LTD.) and 85 parts of ethylacetate, and the mixture was heated to 78° C. so that the wax wasthoroughly dissolved. The resultant mixture was cooled to 30° C. for 1hour while being stirred and then was wet-milled using ULTRAVISCOMILL(product of Aimex CO. LTD.) under the following conditions:liquid-feeding rate: 1.0 kg/hr; disc-circumference speed: 10 m/sec;volume of 0.5-mm zirconia beads packed: 80% by volume; and pass time: 6.Finally, ethyl acetate was added to the resultant mixture so that thesolid content concentration thereof became 15% by mass, whereby[releasing agent dispersion liquid 1] was obtained.

Example 1

A beaker was charged with 84 parts of the [resin a-1], 32 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 84 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 1] was obtained.

To the beaker were added 99 parts of ion exchange water, 6 parts of 25%by mass aqueous dispersion liquid of fine organic particles forstabilizing dispersion (copolymer of styrene-methacrylic acid-butylacrylate-sodium salt of sulfuric acid ester of methacrylic acid ethyleneoxide adduct), 1 part of sodium carboxymethyl cellulose and 10 parts of48.5% by mass aqueous solution of sodium dodecyl diphenyl etherdisulfonate (“ELEMINOL MON-7,” product of Sanyo Chemical IndustriesLtd.) and the components were homogeneously dissolved.

Next, 75 parts of the [toner material liquid 1] was added to the mixturewhile the mixture was being stirred 50° C. with a TK homomixer at 10,000rpm, and the resultant mixture was stirred for 2 min.

Subsequently, the obtained mixture was transferred to a flask equippedwith a stirring rod and a thermometer, and was evaporated at 55° C.until the concentration of the ethyl acetate became 0.5% by mass orlower, whereby [aqueous resin dispersion of resin particles 1] wasobtained.

Thereafter, the following pre-washing step was performed. Specifically,the [aqueous resin dispersion of resin particles 1] was cooled to roomtemperature, followed by filtration, and 300 parts of ion exchange waterwas added to the obtained filtration cake. Then, the resultant mixturewas mixed using a TK homomixer at 12,000 rpm for 10 min and filtrated.This treatment of addition/mixing/filtration was performed twice.

Next, 300 parts of ion exchange water was added to the obtainedfiltration cake. Then, the resultant mixture was mixed using a TKhomomixer at 12,000 rpm for 10 min and filtrated. This treatment ofaddition/mixing/filtration was performed three times. Subsequently, 300parts of 1% by mass hydrochloric acid was added to the obtainedfiltration cake and the resultant mixture was mixed using a TK homomixerat 12,000 rpm for 10 min and filtrated. Finally, 300 parts of ionexchange water was added to the obtained filtration cake and theresultant mixture was mixed using a TK homomixer at 12,000 rpm for 10min and filtrated, where this treatment of addition/mixing/filtrationwas performed twice to thereby obtain a filtration cake.

The obtained cake was beaten and dried at 40° C. for 22 hours, tothereby obtain [resin particles 1] having a volume average particlediameter of 5.6 μm.

Next, 100 parts of the obtained [resin particles 1] and 1.0 part ofhydrophobic silica (H2000, product of Clariant Japan, CO. LTD.) servingas an external additive were mixed together using HENSCHEL MIXER(product of NIPPON COKE & ENGINEERING CO. LTD.) at a circumferentialspeed of 30 m/sec with five cycles each consisting of mixing for 30 secand suspending for 1 min. The resultant mixture was sieved with a meshhaving an opening size of 35 μm to produce toner (1-1).

The integrated molecular weight distribution curve of the obtained toner(1-1) is shown in FIG. 3.

Example 2

A beaker was charged with 89 parts of the [resin a-1], 22 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 89 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 2] was obtained. The rest of the procedure was performed in thesame manner as in Example 1, except that the [toner material liquid 1]was changed to the [toner material liquid 2], to thereby produce toner(1-2).

Example 3

A beaker was charged with 94 parts of the [resin a-1], 12 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 94 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 3] was obtained. The rest of the procedure was performed in thesame manner as in Example 1, except that the [toner material liquid 1]was changed to the [toner material liquid 3], to thereby produce toner(1-3).

Example 4

A beaker was charged with 75 parts of the [resin a-1], 50 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 75 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 4] was obtained. The rest of the procedure was performed in thesame manner as in Example 1, except that the [toner material liquid 1]was changed to the [toner material liquid 4], to thereby produce toner(1-4).

Example 5

A beaker was charged with 80 parts of the [resin a-2], 40 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 80 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 5] was obtained. The rest of the procedure was performed in thesame manner as in Example 1, except that the [toner material liquid 1]was changed to the [toner material liquid 5], to thereby produce toner(1-5).

Example 6

A beaker was charged with 68 parts of the [resin a-3], 64 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 68 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 6] was obtained. The rest of the procedure was performed in thesame manner as in Example 1, except that the [toner material liquid 1]was changed to the [toner material liquid 6], to thereby produce toner(1-6).

Example 7

A beaker was charged with 100 parts of the [resin a-4], 14 parts of the[releasing agent dispersion liquid 1], 10 parts of the [colorantdispersion liquid 1] and 100 parts of ethyl acetate, and the resin wasdissolved while the mixture was being stirred at 50° C. The resultantmixture was stirred with a TK homomixer at 8,000 rpm and the resin washomogeneous dispersed, whereby [toner material liquid 7] was obtained.The rest of the procedure was performed in the same manner as in Example1, except that the [toner material liquid 1] was changed to the [tonermaterial liquid 7], to thereby produce toner (1-7).

Example 8

The procedure of Example 7 was repeated, except that the [resin a-4] waschanged to the [resin a-5], to thereby produce toner (1-8).

Example 9

The procedure of Example 7 was repeated, except that the [resin a-4] waschanged to the [resin a-6], to thereby produce toner (1-9).

Example 10

A beaker was charged with 84 parts of the [resin a-1], 4 parts of the[resin b-1], 28 parts of the [resin b-2], 14 parts of the [releasingagent dispersion liquid 1], 10 parts of the [colorant dispersion liquid1] and 84 parts of ethyl acetate, and the resin was dissolved while themixture was being stirred at 50° C. The resultant mixture was stirredwith a TK homomixer at 8,000 rpm and the resin was homogeneousdispersed, whereby [toner material liquid 10] was obtained. The rest ofthe procedure was performed in the same manner as in Example 1, exceptthat the [toner material liquid 1] was changed to the [toner materialliquid 10], to thereby produce toner (1-10).

Example 11

The procedure of Example 1 was repeated, except that the [resin b-1] waschanged to the [resin b-2], to thereby produce toner (1-11).

Comparative Example 1

A beaker was charged with 72 parts of the [resin a-1], 56 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 72 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 101] was obtained. The rest of the procedure was performed in thesame manner as in Example 1, except that the [toner material liquid 1]was changed to the [toner material liquid 101], to thereby produce toner(101).

Comparative Example 2

A beaker was charged with 97 parts of the [resin a-1], 6 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 97 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 102] was obtained. The rest of the procedure was performed in thesame manner as in Example 1, except that the [toner material liquid 1]was changed to the [toner material liquid 102], to thereby produce toner(102).

Comparative Example 3

A beaker was charged with 86 parts of the [resin a-3], 28 parts of the[resin b-1], 14 parts of the [releasing agent dispersion liquid 1], 10parts of the [colorant dispersion liquid 1] and 86 parts of ethylacetate, and the resin was dissolved while the mixture was being stirredat 50° C. The resultant mixture was stirred with a TK homomixer at 8,000rpm and the resin was homogeneous dispersed, whereby [toner materialliquid 103] was obtained. The rest of the procedure was performed in thesame manner as in Example 1, except that the [toner material liquid 1]was changed to the [toner material liquid 103], to thereby produce toner(103).

[Evaluation Methods]

In the below-described methods, each of the toners obtained in Examplesand Comparative Examples was evaluated for fixability, and an imageformed therewith was evaluated for glossiness.

<Fixability>

As a thin paper sheet was used a paper sheet of long grain: i.e., copypaper sheet <55> (product of Ricoh Company, Ltd.) (described as “55T” inTable 1-3) and as a thick paper sheet was used a paper sheet of longgrain: i.e., copy paper sheet <135> (product of Ricoh Company, Ltd.)(described as “135T” in Table 1-3). A solid image having a width of 50mm was formed on the thin or thick paper sheet so that the tonerdeposition amount became 0.85±0.1 mg/cm². There was used an apparatusformed by modifying the fixing portion of an electrophotographic copier(MF-200, product of Ricoh Company, Ltd.) containing a TEFLON (registeredtrademark) roller as a fixing roller. The paper sheet having the solidimage was fed to this apparatus under conditions that the temperature ofthe fixing belt was set to 120° C. with external control and the linearvelocity of the belt was set to 300 mm/min, to thereby confirm whetheror not offset occurred. Needless to say, the occurrence of offset is notpreferred since it degrades printing quality considerably.

Next, using draw tester AD-401 (product of Ueshima Seisakusho Co.,Ltd.), a sapphire needle (radium: 125 μm) was moved at a state of beingin contact with the colored portion of the fixed image under conditionsthat the rotation diameter of the needle was 8 mm and the load was 1 g.The portion where the needle had been moved was rubbed with a waste fivetimes and then the state of the image was evaluated according to thefollowing evaluation criteria.

A: There was no loss of the image.

B: After rubbing, slight image loss occurred as scratched traces.

C: After rubbing, clear image loss occurred as scratched traces.

D: After rubbing, not only the scratched portions but also the otherimage portions were peeled off.

[Glossiness]

The 60-degree glossiness of the image was measured using a glossimeter(VG-700, product of NIPPON DENSHOKU INDUSTRIES CO., LTD.). Theglossiness is preferably 5 or more, more preferably 10 or more. Thedifference in glossiness between the thin paper and the thick paper(described as “Difference” in Table 1-3) is preferably smaller; i.e.,less than 4, more preferably less than 2. When the difference inglossiness therebetween is great, the difference in image between on thethin paper and on the thick paper becomes considerable to give differentimpressions, which is not preferred. This requires controlling the imageglossiness by separately changing the fixing temperature and the fixingspeed.

<<Fixability (Minimum Fixing Temperature)>>

Using a tandem full-color image forming apparatus 100C depicted in FIG.6, a solid image having an image size of 3 cm×8 cm was formed on a papersheet (product of Ricoh Business Expert, Ltd., a copy paper sheet <70>),the solid image having a toner deposition amount of 0.85±0.10 mg/cm².Then, the formed solid image was fixed with the temperature of thefixing belt changed. The fixed image surface was drawn with a rubyneedle (tip radius: 260 μmR to 320 μmR, tip angle: 60 degrees) at a loadof 50 g using draw tester AD-401 (product of Ueshima Seisakusho Co.,Ltd.). The drawn image surface was strongly rubbed five times with afabric (HONECOTTO #440, Hanylon Co. Ltd.). Here, the temperature of thefixing belt at which almost no peeling-off of the image occurred wasdetermined as the minimum fixing temperature. The solid image was formedon the paper sheet at a position 3.0 cm away from an edge of the papersheet that entered the image forming apparatus. Notably, the speed atwhich the paper sheet passed through the nip portion of the fixingdevice was 280 mm/s. The lower minimum fixing temperature means the moreexcellent low-temperature fixability.

[Evaluation Criteria]

A: Minimum fixing temperature≦105° C.

B: 105° C.<Minimum fixing temperature≦115° C.

C: 115° C.<Minimum fixing temperature≦130° C.

D: 130° C.<Minimum fixing temperature

<<Fixability (Hot Offset Resistance, Fixable Range)>>

Using a tandem full-color image forming apparatus 100C depicted in FIG.6, a solid image having an image size of 3 cm×8 cm was formed on a papersheet (product of Ricoh Company, Ltd., Type 6200), the solid imagehaving a toner deposition amount of 0.85±0.10 mg/cm². Then, the formedsolid image was fixed with the temperature of the fixing belt changed,to thereby visually evaluate whether or not hot offset occurred. Here,the fixable range is a difference between the minimum fixing temperatureand the maximum temperature at which no hot offset occurred. The solidimage was formed on the paper sheet at a position 3.0 cm away from anedge of the paper sheet that entered the image forming apparatus.Notably, the speed at which the paper sheet passed through the nipportion of the fixing device was 280 mm/s. The wider fixable range meansthe more excellent hot offset resistance. Conventional full-color tonershave a fixable range of about 50° C. on average.

[Evaluation Criteria]

A: 100° C.<Fixable range

B: 55° C.<Fixable range 100° C.

C: 30° C.<Fixable range 55° C.

D: Fixable range 30° C.

<<Heat Resistance Storage Stability (Penetration Degree)>>

Each toner was charged into a 50-mL glass container and left to stand ina thermostat bath of 50° C. for 24 hours. The thus-treated toner wascooled to 24° C. and then measured for penetration degree (mm) by thepenetration degree test (JISK2235-1991) and evaluated according to thefollowing evaluation criteria. Notably, the greater penetration degreemeans the more excellent heat resistance storage stability. Toner havinga penetration degree of less than 5 mm is highly likely to involveproblems in use.

Notably, the penetration degree in the present invention is expressed bythe penetration depth (mm).

[Evaluation Criteria]

A: 25 mm≦Penetration degree

B: 15 mm≦Penetration degree<25 mm

C: 5 mm≦Penetration degree<15 mm

D: Penetration degree<5 mm

<<Stress Resistance>>

Using a tandem full-color image forming apparatus 100C depicted in FIG.6, a chart having an image occupation rate of 0.5% was formed on 50,000sheets. Thereafter, a solid image was formed on a sheet and the obtainedsheet was visually observed for whether the image portion had whitespots free of the toner and evaluated according to the followingevaluation criteria.

[Evaluation Criteria]

A: White spots free of the toner were not observed in the image portion;excellent state

B: Few white spots free of the toner were observed in the image portion;good state

C: Some white spots free of the toner were observed in the imageportion; but non-problematic in practical use

D: Numerous white spots free of the toner were observed in the imageportion; and problematic in practical use

<<Transferability>>

Using a tandem full-color image forming apparatus 100C depicted in FIG.6, a chart having an image occupation rate of 0.5% was formed on 50,000sheets. Thereafter, in the course of formation of a solid image on asheet, the image forming apparatus was stopped in operation immediatelyafter the image had been transferred from a photoconductor (10) to anintermediate transfer belt (50). The photoconductor was taken out andthen visually observed for untransfered toner remaining the transferportion thereof and evaluated according to the following evaluationcriteria. The evaluation results are shown in Table 9-2.

[Evaluation Criteria]

A: No untransferred toner was observed on the photoconductor; excellentstate

B: Untransferred toner was slightly observed on the photoconductor tosuch an extent that the color of the background of the photoconductorcould be perceived; good state

C: Untransferred toner was observed on the photoconductor and thebackground of the photoconductor was somewhat covered therewith; butnon-problematic in practical use

D: Much untransferred toner was observed on the photoconductor and thebackground of the photoconductor was almost covered therewith; andproblematic in practical use

The evaluation results are shown in Table 1-3.

TABLE 1-1 Formulation Resin-1 Resin-2 Resin-3 Compositinal CompositinalCompositinal ratio on ratio ratio on solid on solid solid Propertiescontent content content 100,000 250,000 Type basis Type basis Type basisMn Mw Mpt or more or more Mw/Mn Ex. 1 Resin a-1 84 Resin b-1 16 — —12,077 52,900 43,197 9.9 0.7 4.38 Ex. 2 Resin a-1 89 Resin b-1 11 — —11,800 48,400 41,500 7.9 0.5 4.10 Ex. 3 Resin a-1 94 Resin b-1 6 — —11,100 43,480 38,900 5.6 0.4 3.92 Ex. 4 Resin a-1 75 Resin b-1 25 — —15,330 59,800 48,800 15.0 1.3 3.90 Ex. 5 Resin a-2 80 Resin b-1 20 — —13,600 50,100 45,200 10.8 0.9 3.68 Ex. 6 Resin a-3 68 Resin b-1 32 — —10,500 40,200 35,600 17.3 1.7 3.83 Ex. 7 Resin a-4 100 — — — — 6,50042,100 32,600 5.1 0.4 6.48 Ex. 8 Resin a-5 100 — — — — 5,600 40,60030,700 5.0 0.4 7.25 Ex. 9 Resin a-6 100 — — — — 5,900 41,100 31,400 5.10.6 6.97 Ex. 10 Resin a-1 84 Resin b-1 2 Resin b-2 14 11,400 48,80036,500 7.1 0.6 4.28 Ex. 11 Resin a-1 84 Resin b-2 16 — — 11,500 47,80037,700 7.3 0.6 4.16 Comp. Resin a-1 72 Resin b-1 28 — — 16,000 61,80050,500 16.1 1.4 3.86 Ex. 1 Comp. Resin a-1 97 Resin b-1 3 — — 10,70040,700 37,700 4.6 0.2 3.80 Ex. 2 Comp. Resin a-3 86 Resin b-1 14 — —7,800 19,700 18,200 8.6 0.6 2.53 Ex. 3

TABLE 1-2 THF/AcOE insoluble N matter (% by mass) Urethane Urea(C)/((C) + (A)) (% by mass) ΔH(T) ΔH(H) ΔH(H)/ΔH(T) Ex. 1 1.54 PresencePresence 0.27 14.0 60.8 46.2 0.76 Ex. 2 1.59 Presence Presence 0.25 10.857.8 41.3 0.71 Ex. 3 1.64 Presence Presence 0.22 9.2 52.5 33.7 0.64 Ex.4 1.45 Presence Presence 0.29 14.9 63.3 55.5 0.88 Ex. 5 0.46 PresencePresence 0.31 14.7 79.2 75.1 0.95 Ex. 6 1.65 Presence Presence 0.27 17.051.1 62.9 1.23 Ex. 7 <0.01 Absence Absence 0.42 8.8 88.5 85.4 0.96 Ex. 80.67 Presence Absence 0.29 10.2 74.3 72.2 0.97 Ex. 9 0.66 PresencePresence 0.28 10.6 72.9 71.4 0.98 Ex. 10 1.51 Presence Presence 0.19 7.948.1 18.3 0.38 Ex. 11 1.51 Presence Presence 0.18 12.3 45.2 8.1 0.18Comp. 1.42 Presence Presence 0.30 15.8 65.6 57.3 0.87 Ex. 1 Comp. 1.67Presence Presence 0.20 8.2 50.8 31.2 0.61 Ex. 2 Comp. 1.82 PresencePresence 0.24 12.8 49.9 50.3 1.01 Ex. 3

TABLE 1-3 Evaluation for fixation Heat Post-fixation resistanceFixability state Glossiness Min. Fixable storage Stress 55T 135T 55T135T 55T 135T Difference temp. range stability resistanceTransferability Ex. 1 A B A A 9.4 8.3 1.1 C B A A A Ex. 2 A A A A 13.512.1 1.4 B A A A A Ex. 3 A A A A 21.1 16.8 4.3 B C B A A Ex. 4 A B B C4.5 4.2 0.3 C B A A A Ex. 5 A B A A 12.7 11.9 0.8 C B A C C Ex. 6 B A BC 2.8 2.4 0.4 B A B A A Ex. 7 C B B B 24.9 19.2 5.7 C C A C C Ex. 8 B AA B 19.0 17.3 1.7 A C A B B Ex. 9 B A A A 15.7 15.2 0.5 A C A B B Ex. 10C A A A 18.5 12.3 6.2 C B C A A Ex. 11 C C A A 21.6 11.9 9.7 C B C C CComp. B B D D 2.0 1.7 0.3 C B A A A Ex. 1 Comp. D A A A — 19.8 — D C B AA Ex. 2 Comp. D B A A — 11.9 — D C C A A Ex. 3

Production Example 1 Production of Crystalline Polyurethane Resin A-1

A reaction container to which a stirrer and a thermometer had been setwas charged with 45 parts of 1,4-butanediol (0.50 mol), 59 parts of1,6-hexanediol (0.50 mol) and 200 parts of methyl ethyl ketone(hereinafter abbreviated as “MEK”). Then, 250 parts of4,4′-diphenylmethane diisocyanate (MDI) (1.00 mol) was added to theresultant solution, followed by being allowed to react at 80° C. for 5hours. Subsequently, the solvent was removed to obtain [crystallinepolyurethane resin A-1]. The obtained [crystalline polyurethane resinA-1] was found to have a Mw of 20,000 and a melting point of 60° C.

Production Example 2 Production of Urethane-Modified CrystallinePolyester Resin A-2

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 15 parts of adipic acid (0.10 mol), 177 parts of1,6-hexanediol (1.50 mol) and 0.5 parts of tetrabutoxy titanate servingas a condensing catalyst, and the resultant mixture was allowed to reactunder nitrogen flow at 180° C. for 8 hours while the water formed wasbeing removed. Next, the reaction mixture was allowed to react for 4hours under nitrogen flow while the water formed and the 1,6-hexanediolwere being removed with the temperature of the reaction mixturegradually increased to 220° C. Furthermore, the reaction mixture wasallowed to further react at a reduced pressure of 5 mmHg to 20 mmHguntil the Mw of the reaction product reached about 12,000, whereby[crystalline polyester resin A′-2] was obtained. The obtained[crystalline polyester resin A′-2] was found to have a Mw of 12,000.

Next, the obtained [crystalline polyester resin A′-2] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 350 parts of ethyl acetate and 30 partsof 4,4′-diphenylmethane diisocyanate (MDI) (0.12 mol) were addedthereto, followed by being allowed to react under nitrogen flow at 80°C. for 5 hours. Next, the ethyl acetate was evaporated under reducedpressure to obtain [urethane-modified crystalline polyester resin A-2].The obtained (urethane-modified crystalline polyester resin A-21 wasfound to have a Mw of 22,000 and a melting point of 62° C.

Production Example 3 Production of Urethane-Modified CrystallinePolyester Resin A-3

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 189 parts of 1,6-hexanediol (1.60 mol) and 0.5 parts ofdibutyltin oxide serving as a condensing catalyst, and the resultantmixture was allowed to react under nitrogen flow at 180° C. for 8 hourswhile the water formed was being removed. Next, the reaction mixture wasallowed to react for 4 hours under nitrogen flow while the water formedand the 1,6-hexanediol were being removed with the temperature of thereaction mixture gradually increased to 220° C. Furthermore, thereaction mixture was allowed to further react at a reduced pressure of 5mmHg to 20 mmHg until the Mw of the reaction product reached about6,000, whereby [crystalline polyester resin A′-3] was obtained. Theobtained [crystalline polyester resin A′-3] was found to have a Mw of6,000.

Next, the obtained [crystalline polyester resin A′-3] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 300 parts of ethyl acetate and 38 partsof 4,4′-diphenylmethane diisocyanate (MDI) (0.15 mol) were addedthereto, followed by being allowed to react under nitrogen flow at 80°C. for 5 hours. Next, the ethyl acetate was evaporated under reducedpressure to obtain [urethane-modified crystalline polyester resin A-3].The obtained [urethane-modified crystalline polyester resin A-3] wasfound to have a Mw of 10,000 and a melting point of 64° C.

Production Example 4 Production of Urethane-Modified CrystallinePolyester Resin A-4

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 185 parts of sebacic acid(0.91 mol), 13 parts of adipic acid (0.09 mol), 106 parts of1,4-butanediol (1.18 mol) and 0.5 parts of titaniumdihydroxybis(triethanolaminate) serving as a condensing catalyst, andthe resultant mixture was allowed to react under nitrogen flow at 180°C. for 8 hours while the water formed was being removed. Next, thereaction mixture was allowed to react for 4 hours under nitrogen flowwhile the water formed and the 1,4-butanediol were being removed withthe temperature of the reaction mixture gradually increased to 220° C.Furthermore, the reaction mixture was allowed to further react at areduced pressure of 5 mmHg to 20 mmHg until the Mw of the reactionproduct reached about 14,000, whereby [crystalline polyester resin A′-4]was obtained. The obtained [crystalline polyester resin A′-4] was foundto have a Mw of 14,000.

Next, the obtained [crystalline polyester resin A′-4] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 250 parts of ethyl acetate and 12 partsof hexamethylene diisocyanate (HDI) (0.07 mol) were added thereto,followed by being allowed to react under nitrogen flow at 80° C. for 5hours. Next, the ethyl acetate was evaporated under reduced pressure toobtain [urethane-modified crystalline polyester resin A-4]. The obtained[urethane-modified crystalline polyester resin A-4] was found to have aMw of 39,000 and a melting point of 63° C.

Production Example 5 Production of Urethane-Modified CrystallinePolyester Resin A-5

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 166 parts of sebacic acid(0.82 mol), 26 parts of adipic acid (0.18 mol), 131 parts of1,4-butanediol (1.45 mol) and 0.5 parts of titaniumdihydroxybis(triethanolaminate) serving as a condensing catalyst, andthe resultant mixture was allowed to react under nitrogen flow at 180°C. for 8 hours while the water formed was being removed. Next, thereaction mixture was allowed to react for 4 hours under nitrogen flowwhile the water formed and the 1,4-butanediol were being removed withthe temperature of the reaction mixture gradually increased to 220° C.Furthermore, the reaction mixture was allowed to further react at areduced pressure of 5 mmHg to 20 mmHg until the Mw of the reactionproduct reached about 8,000, whereby [crystalline polyester resin A′-5]was obtained. The obtained [crystalline polyester resin A′-5] was foundto have a Mw of 8,000.

Next, the obtained [crystalline polyester resin A′-5] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 250 parts of ethyl acetate and 33 partsof 4,4′-diphenylmethane diisocyanate (MDI) (0.13 mol) were addedthereto, followed by being allowed to react under nitrogen flow at 80°C. for 5 hours. Next, the ethyl acetate was evaporated under reducedpressure to obtain [urethane-modified crystalline polyester resin A-5].The obtained [urethane-modified crystalline polyester resin A-5] wasfound to have a Mw of 17,000 and a melting point of 54° C.

Production Example 6 Production of Urethane-Modified CrystallinePolyester Resin A-6

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 18 parts of adipic acid (0.12 mol), 139 parts of1,6-hexanediol (1.18 mol) and 0.5 parts of tetrabutoxy titanate servingas a condensing catalyst, and the resultant mixture was allowed to reactunder nitrogen flow at 180° C. for 8 hours while the water formed wasbeing removed. Next, the reaction mixture was allowed to react for 4hours under nitrogen flow while the water formed and the 1,6-hexanediolwere being removed with the temperature of the reaction mixturegradually increased to 220° C. Furthermore, the reaction mixture wasallowed to further react at a reduced pressure of 5 mmHg to 20 mmHguntil the Mw of the reaction product reached about 18,000, whereby[crystalline polyester resin A′-6] was obtained. The obtained[crystalline polyester resin A′-6] was found to have a Mw of 18,000.

Next, the obtained [crystalline polyester resin A′-6] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 250 parts of ethyl acetate and 15 partsof 4,4′-diphenylmethane diisocyanate (MDI) (0.06 mol) were addedthereto, followed by being allowed to react under nitrogen flow at 80°C. for 5 hours. Next, the ethyl acetate was evaporated under reducedpressure to obtain [urethane-modified crystalline polyester resin A-6].The obtained [urethane-modified crystalline polyester resin A-6] wasfound to have a Mw of 42,000 and a melting point of 62° C.

Production Example 7 Production of Urethane-Modified CrystallinePolyester Resin A-7

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 149 parts of 1,6-hexanediol (1.26 mol) and 0.5 parts oftetrabutoxy titanate serving as a condensing catalyst, and the resultantmixture was allowed to react under nitrogen flow at 180° C. for 8 hourswhile the water formed was being removed. Next, the reaction mixture wasallowed to react for 4 hours under nitrogen flow while the water formedand the 1,6-hexanediol were being removed with the temperature of thereaction mixture gradually increased to 220° C. Furthermore, thereaction mixture was allowed to further react at a reduced pressure of 5mmHg to 20 mmHg until the Mw of the reaction product reached about9,000, whereby [crystalline polyester resin A′-7] was obtained. Theobtained [crystalline polyester resin A′-7] was found to have a Mw of9,000.

Next, the obtained [crystalline polyester resin A′-7] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 250 parts of ethyl acetate and 28 partsof 4,4′-diphenylmethane diisocyanate (MDI) (0.11 mol) were addedthereto, followed by being allowed to react under nitrogen flow at 80°C. for 5 hours. Next, the ethyl acetate was evaporated under reducedpressure to obtain [urethane-modified crystalline polyester resin A-7].The obtained [urethane-modified crystalline polyester resin A-7] wasfound to have a Mw of 30,000 and a melting point of 67° C.

Production Example 8 Production of Urethane-Modified CrystallinePolyester Resin A-8

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 191 parts of 1,6-hexanediol (1.62 mol) and 0.5 parts oftetrabutoxy titanate serving as a condensing catalyst, and the resultantmixture was allowed to react under nitrogen flow at 180° C. for 8 hourswhile the water formed was being removed. Next, the reaction mixture wasallowed to react for 4 hours under nitrogen flow while the water formedand the 1,6-hexanediol were being removed with the temperature of thereaction mixture gradually increased to 220° C. Furthermore, thereaction mixture was allowed to further react at a reduced pressure of 5mmHg to 20 mmHg until the Mw of the reaction product reached about4,000, whereby [crystalline polyester resin A′-8] was obtained. Theobtained [crystalline polyester resin A′-8] was found to have a Mw of4,000.

Next, the obtained [crystalline polyester resin A′-8] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 300 parts of ethyl acetate and 35 partsof 4,4′-diphenylmethane diisocyanate (MDI) (0.14 mol) were addedthereto, followed by being allowed to react under nitrogen flow at 80°C. for 5 hours. Next, the ethyl acetate was evaporated under reducedpressure to obtain [urethane-modified crystalline polyester resin A-8].The obtained [urethane-modified crystalline polyester resin A-8] wasfound to have a Mw of 8,500 and a melting point of 64° C.

Production Example 9 Production of Crystalline Polyurea Resin A-9

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 123 parts of1,4-butanediamine (1.40 mol), 212 parts of 1,6-hexanediamine (1.82 mol)and 100 parts of methyl ethyl ketone (MEK), followed by stirring. Then,336 parts of hexamethylene diisocyanate (HDI) (2.00 mol) was added tothe resultant mixture, which was allowed to react under nitrogen flow at60° C. for 5 hours. Next, the MEK was evaporated under reduced pressureto obtain [crystalline polyurea resin A-9]. The obtained [crystallinepolyurea resin A-9] was found to have a Mw of 23,000 and a melting pointof 64° C.

Production Example 10 Production of Crystalline Polyester Resin A-10

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 185 parts of sebacic acid(0.91 mol), 13 parts of adipic acid (0.09 mol), 125 parts of1,4-butanediol (1.39 mol) and 0.5 parts of titaniumdihydroxybis(triethanolaminate) serving as a condensing catalyst, andthe resultant mixture was allowed to react under nitrogen flow at 180°C. for 8 hours while the water formed was being removed. Next, thereaction mixture was allowed to react for 4 hours under nitrogen flowwhile the water formed and the 1,4-butanediol were being removed withthe temperature of the reaction mixture gradually increased to 220° C.Furthermore, the reaction mixture was allowed to further react at areduced pressure of 5 mmHg to 20 mmHg until the Mw of the reactionproduct reached about 10,000, whereby [crystalline polyester resin A-10]was obtained. The obtained [crystalline polyester resin A-10] was foundto have a Mw of 9,500 and a melting point of 57° C.

Production Example 11 Production of Crystalline Polyester Resin A-11

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 130 parts of 1,6-hexanediol (1.10 mol) and 0.5 parts oftetrabutoxy titanate serving as a condensing catalyst, and the resultantmixture was allowed to react under nitrogen flow at 180° C. for 8 hourswhile the water formed was being removed. Next, the reaction mixture wasallowed to react for 4 hours under nitrogen flow while the water formedand the 1,6-hexanediol were being removed with the temperature of thereaction mixture gradually increased to 220° C. Furthermore, thereaction mixture was allowed to further react at a reduced pressure of 5mmHg to 20 mmHg until the Mw of the reaction product reached about30,000, whereby [crystalline polyester resin A-11] was obtained. Theobtained [crystalline polyester resin A-11] was found to have a Mw of27,000 and a melting point of 62° C.

Production Example 12 Production of Block Resin A-12 Composed ofCrystalline Portions and Non-Crystalline Portions

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 25 parts of 1,2-propyleneglycol (0.33 mol) and 170 parts of methyl ethyl ketone (MEK), followedby stirring. Then, 147 parts of 4,4′-diphenylmethane diisocyanate (MDI)(0.59 mol) was added to the resultant mixture, which was allowed toreact at 80° C. for 5 hours, to thereby obtain a MEK solution of[non-crystalline portion c-1] having an isocyanate group at the endsthereof.

Separately, a reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 160 parts of 1,6-hexanediol (1.35 mol) and 0.5 parts oftetrabutoxy titanate serving as a condensing catalyst, and the resultantmixture was allowed to react under nitrogen flow at 180° C. for 8 hourswhile the water formed was being removed. Next, the reaction mixture wasallowed to react for 4 hours under nitrogen flow while the water formedand the 1,6-hexanediol were being removed with the temperature of thereaction mixture gradually increased to 220° C. Furthermore, thereaction mixture was allowed to further react at a reduced pressure of 5mmHg to 20 mmHg until the Mw of the reaction product reached about9,000, whereby [crystalline polyester resin A′-12] was obtained. Theobtained [crystalline polyester resin A′-12] was found to have a Mw of8,500 and a melting point of 63° C.

Next, 320 parts of the [crystalline polyester resin A′-12] was dissolvedin 320 parts of MEK, and the solution was added as crystalline portionsto 340 parts of the MEK solution of [non-crystalline portion c-1]. Theresultant mixture was allowed to react under nitrogen at 80° C. for 5hours. Subsequently, the MEK was evaporated under reduced pressure toobtain [block resin A-12]. The obtained [block resin A-12] was found tohave a Mw of 26,000 and a melting point of 62° C.

Production Example 13 Production of Block Resin A-13 Composed ofCrystalline Portions and Non-Crystalline Portions

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 39 parts of 1,2-propyleneglycol (0.51 mol) and 270 parts of methyl ethyl ketone (MEK), followedby stirring. Then, 228 parts of 4,4′-diphenylmethane diisocyanate (MDI)(0.91 mol) was added to the resultant mixture, which was allowed toreact at 80° C. for 5 hours, to thereby obtain a MEK solution of[non-crystalline portion c-2] having an isocyanate group at the endsthereof.

Separately, a reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 160 parts of 1,6-hexanediol (1.35 mol) and 0.5 parts oftetrabutoxy titanate serving as a condensing catalyst, and the resultantmixture was allowed to react under nitrogen flow at 180° C. for 8 hourswhile the water formed was being removed. Next, the reaction mixture wasallowed to react for 4 hours under nitrogen flow while the water formedand the 1,6-hexanediol were being removed with the temperature of thereaction mixture gradually increased to 220° C. Furthermore, thereaction mixture was allowed to further react at a reduced pressure of 5mmHg to 20 mmHg until the Mw of the reaction product reached about8,000, whereby [crystalline polyester resin A′-13] was obtained. Theobtained [crystalline polyester resin A′-13] was found to have a Mw of7,500 and a melting point of 62° C.

Next, 320 parts of the [crystalline polyester resin A′-13] was dissolvedin 320 parts of MEK, and the solution was added as crystalline portionsto 540 parts of the MEK solution of [non-crystalline portion c-2]. Theresultant mixture was allowed to react under nitrogen at 80° C. for 5hours. Subsequently, the MEK was evaporated under reduced pressure toobtain [block resin A-13]. The obtained [block resin A-13] was found tohave a Mw of 23,000 and a melting point of 61° C.

Production Example 14 Production of Urethane-Modified CrystallinePolyester Resin B-1

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 113 parts of sebacic acid(0.56 mol), 109 parts of dimethyl terephthalate (0.56 mol), 132 parts of1,6-hexanediol (1.12 mol) and 0.5 parts of titaniumdihydroxybis(triethanolaminate) serving as a condensing catalyst, andthe resultant mixture was allowed to react under nitrogen flow at 180°C. for 8 hours while the water and methanol formed were being removed.Next, the reaction mixture was allowed to react for 4 hours undernitrogen flow while the water formed and the 1,6-hexanediol were beingremoved with the temperature of the reaction mixture gradually increasedto 220° C. Furthermore, the reaction mixture was allowed to furtherreact at a reduced pressure of 5 mmHg to 20 mmHg until the Mw of thereaction product reached about 35,000, whereby [crystalline polyesterresin B′-1] was obtained. The obtained [crystalline polyester resinB′-1] was found to have a Mw of 34,000.

Next, the obtained [crystalline polyester resin B′-1] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 200 parts of ethyl acetate and 10 partsof hexamethylene diisocyanate (HDI) (0.06 mol) were added thereto,followed by being allowed to react under nitrogen flow at 80° C. for 5hours. Next, the ethyl acetate was evaporated under reduced pressure toobtain [urethane-modified crystalline polyester resin B-1]. The obtained[urethane-modified crystalline polyester resin B-1] was found to have aMw of 63,000 and a melting point of 65° C.

Production Example 15 Production of Urethane-Modified CrystallinePolyester Resin B-2

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 204 parts of sebacic acid(1.01 mol), 13 parts of adipic acid (0.09 mol), 136 parts of1,6-hexanediol (1.15 mol) and 0.5 parts of tetrabutoxy titanate servingas a condensing catalyst, and the resultant mixture was allowed to reactunder nitrogen flow at 180° C. for 8 hours while the water formed wasbeing removed. Next, the reaction mixture was allowed to react for 4hours under nitrogen flow while the water formed and the 1,6-hexanediolwere being removed with the temperature of the reaction mixturegradually increased to 220° C. Furthermore, the reaction mixture wasallowed to further react at a reduced pressure of 5 mmHg to 20 mmHguntil the Mw of the reaction product reached about 20,000, whereby[crystalline polyester resin B′-2] was obtained. The obtained[crystalline polyester resin B′-2] was found to have a Mw of 20,000.

Next, the obtained [crystalline polyester resin B′-2] was transferred toa reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube, and 200 parts of ethyl acetate and 15 partsof 4,4′-diphenylmethane diisocyanate (MDI) (0.06 mol) were addedthereto, followed by being allowed to react under nitrogen flow at 80°C. for 5 hours. Next, the ethyl acetate was evaporated under reducedpressure to obtain [urethane-modified crystalline polyester resin B-2].The obtained [urethane-modified crystalline polyester resin B-2] wasfound to have a Mw of 39,000 and a melting point of 63° C.

Production Example 16 Production of Crystalline Polyurea Resin B-3

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 79 parts of 1,4-butanediamine(0.90 mol), 116 parts of 1,6-hexanediamine (1.00 mol) and 600 parts ofmethyl ethyl ketone (MEK), followed by stirring. Then, 475 parts of4,4′-diphenylmethane diisocyanate (MDI) (1.90 mol) was added to theresultant mixture, which was allowed to react under nitrogen flow at 60°C. for 5 hours. Next, the MEK was evaporated under reduced pressure toobtain [crystalline polyurea resin B-3]. The obtained [crystallinepolyurea resin B-3] was found to have a Mw of 57,000 and a melting pointof 66° C.

Production Example 17 Production of Crystalline Polyester Resin B-4

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 230 parts of dodecanedioicacid (1.00 mol), 118 parts of 1,6-hexanediol (1.00 mol) and 0.5 parts oftetrabutoxy titanate serving as a condensing catalyst, and the resultantmixture was allowed to react under nitrogen flow at 180° C. for 8 hourswhile the water formed was being removed. Next, the reaction mixture wasallowed to react for 4 hours under nitrogen flow while the water formedand the 1,6-hexanediol were being removed with the temperature of thereaction mixture gradually increased to 220° C. Furthermore, thereaction mixture was allowed to further react at a reduced pressure of 5mmHg to 20 mmHg until the Mw of the reaction product reached about50,000, whereby [crystalline polyester resin B-4] was obtained. Theobtained [crystalline polyester resin B-4] was found to have a Mw of52,000 and a melting point of 66° C.

Production Example 18 Production of Crystalline Resin Precursor B′-5

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 202 parts of sebacic acid(1.00 mol), 122 parts of 1,6-hexanediol (1.03 mol) and 0.5 parts oftitanium dihydroxybis(triethanolaminate) serving as a condensingcatalyst, and the resultant mixture was allowed to react under nitrogenflow at 180° C. for 8 hours while the water formed was being removed.Next, the reaction mixture was allowed to react for 4 hours undernitrogen flow while the water formed and the 1,6-hexanediol were beingremoved with the temperature of the reaction mixture gradually increasedto 220° C. Furthermore, the reaction mixture was allowed to furtherreact at a reduced pressure of 5 mmHg to 20 mmHg until the Mw of thereaction product reached about 25,000.

The obtained [crystalline resin] was transferred to a reaction vesselequipped with a condenser, a stirrer and a nitrogen-introducing tube,and 300 parts of ethyl acetate and 27 parts of hexamethylenediisocyanate (HDI) (0.16 mol) were added thereto, followed by beingallowed to react under nitrogen flow at 80° C. for 5 hours, to therebyobtain a 50% by mass ethyl acetate solution of [crystalline resinprecursor B′-5] having an isocyanate group on the ends thereof. Next, 10parts of the 50% by mass ethyl acetate solution of [crystalline resinprecursor B′-5] was mixed with 10 parts of tetrahydrofuran (THF), and 1part of dibutylamine was added to the resultant mixture, followed bystirring for 2 hours. The obtained solution was measured through GPC andas a result the [crystalline resin precursor B′-S] was found to have aMw of 54,000. After the solvent had been removed from the abovesolution, the obtained sample was measured through DSC and as a resultthe [crystalline resin precursor B′-5] was found to have a melting pointof 57° C.

Tables 2-1, 2-2, 3 and 4 collectively show the materials used for theproduction of each crystalline resin and properties of the crystallineresin. In Tables 2-1, 2-2, 3 and 4, regarding the amounts of thematerials used in Production Examples, the numerical value in the leftcolumn indicates an amount in “part(s)” and the numerical value in theright column indicates an amount in “mol.” Also, the numerical value inthe column for the catalyst indicates an amount in “part(s).”

TABLE 2-1 Crystalline resin (A) Polyurethane resin Urethane-modifiedpolyester resin A-1 A-2 A-3 A-4 A-5 A-6 Alcohol 1,4-Butanediol 45 0.50106 1.18 131 1.45 component 1,6-Hexanediol 59 0.50 177 1.50 189 1.60 1391.18 Carboxylic Adipic acid 15 0.10 13 0.09 26 0.18 18 0.12 acid Sebacicacid 202 1.00 202 1.00 185 0.91 166 0.82 202 1.00 component IsocyanateHexamethylene 12 0.07 component diisocyanate (HDI) 4,4′-Diphenylmethane250 1.00 30 0.12 38 0.15 33 0.13 15 0.06 diisocyanate (MDI) Amine1,4-Butanediamine component 1,6-Hexanediamine Catalyst Titaniumdihydroxybis 0.5 0.5 (triethanolaminate) Tetrabutoxy titanate 0.5 0.5Dibutyltin oxide 0.5 Tm 60 62 64 63 54 62 Mw 20,000 22,000 10,000 39,00017,000 42,000

TABLE 2-2 Crystalline resin (A) Urethane-modified Polyurea polyesterresin resin Polyester resin A-7 A-8 A-9 A-10 A-11 Alcohol 1,4-Butanediol125 1.39 component 1,6-Hexanediol 149 1.26 191 1.62 130 1.10 CarboxylicAdipic acid 13 0.09 acid Sebacic acid 202 1.00 202 1.00 185 0.91 2021.00 component Isocyanate Hexamethylene diisocyanate 336 2.00 component(HDI) 4,4′-Diphenylmethane 28 0.11 35 0.14 diisocyanate (MDI) Amine1,4-Butanediamine 123 1.40 component 1,6-Hexanediamine 212 1.82 CatalystTitanium 0.5 dihydroxybis(triethanolaminate) Tetrabutoxy titanate 0.50.5 0.5 Dibutyltin oxide Tm 67 64 64 57 62 Mw 30,000 8,500 23,000 9,50027,000

TABLE 3 Crystalline portion/ Non-crystalline portion Block resin A-12A-13 Crystalline 1,2-Propylene glycol 25 0.33 39 0.51 portion4,4′-Diphenylmethane 147 0.59 228 0.91 diisocyanate (MDI) Non-1,6-Hexanediol 160 1.35 160 1.35 crystalline Sebacic acid 202 1.00 2021.00 portion Catalyst Tetrabutoxy titanate 0.5 0.5 Tm 62 61 Mw 26,00023,000

TABLE 4 Crystalline resin (B) Urethane-modified Polyurea PolyesterCrystalline polyester resin resin resin resin precursor B-1 B-2 B-3 B-4B′-5 Alcohol 1,4-Butanediol component 1,6-Hexanediol 132 1.12 136 1.15118 1.00 122 1.03 Carboxylic Adipic acid 13 0.09 acid Sebacic acid 1130.56 204 1.01 202 1.00 component Dodecanedioic acid 230 1.00 Dimethylterephthalate 109 0.56 Isocyanate Hexamethylene diisocyanate 10 0.06 270.16 component (HDI) 4,4′-Diphenylmethane 15 0.06 475 1.90 diisocyanate(MDI) Amine 1,4-Butanediamine 79 0.90 component 1,6-Hexanediamine 1161.00 Catalyst Titanium 0.5 0.5 dihydroxybis(triethanolaminate)Tetrabutoxy titanate 0.5 0.5 Tm 65 63 66 66 57 Mw 63,000 39,000 57,00052,000 54,000

Production Example 19 Production of Non-Crystalline Resin C-1

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 222 parts of bisphenol A EO 2mole adduct, 129 parts of bisphenol A PO 2 mole adduct, 166 parts ofisophthalic acid and 0.5 parts of tetrabutoxy titanate, and theresultant mixture was allowed to react under nitrogen flow and normalpressure at 230° C. for 8 hours while the water formed was beingremoved. Next, the reaction mixture was allowed to react under a reducedpressure of 5 mmHg to 20 mmHg. The reaction mixture was cooled to 180°C. at the time when the acid value thereof became 2. Then, 35 parts oftrimellitic anhydride was added to the reaction mixture, followed bybeing allowed to react under normal pressure for 3 hours, to therebyobtain [non-crystalline resin C-1]. The [non-crystalline resin C-1] wasfound to have a Mw of 8,000 and a Tg of 62° C.

Production Example 20 Production of Non-Crystalline Resin C′-2

A reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 720 parts of bisphenol A EO 2mole adduct, 90 parts of bisphenol A PO 2 mole adduct, 290 parts ofterephthalic acid and 1 part of tetrabutoxy titanate, and the resultantmixture was allowed to react under nitrogen flow and normal pressure at230° C. for 8 hours while the water formed was being removed. Next, thereaction mixture was allowed to react under a reduced pressure of 10mmHg to 15 mmHg for 7 hours, whereby [non-crystalline resin] wasobtained.

Next, a reaction vessel equipped with a condenser, a stirrer and anitrogen-introducing tube was charged with 400 parts of the obtained[non-crystalline resin], 95 parts of isophorone diisocyanate and 500parts of ethyl acetate, and the resultant mixture was allowed to reactunder nitrogen flow at 80° C. for 8 hours, to thereby a 50% by massethyl acetate solution of [non-crystalline resin precursor C′-2] havingan isocyanate group on the ends thereof.

Examples 12 to 24 and Comparative Example 4 to 7 Production of Toner

—Production of Graft Polymer—

A reaction container to which a stirring rod and a thermometer had beenset was charged with 480 parts of xylene and 100 parts of alow-molecular-weight polyethylene (product of Sanyo Chemical Industries,Ltd., SANWAX LEL-400; softening point: 128° C.) and the polyethylene wasthoroughly dissolved. After the reaction container had been purged withnitrogen, a mixture containing styrene (740 parts), acrylonitrile (100parts), butyl acrylate (60 parts), di-t-butylperoxyhexahydroterephthalate (36 parts) and xylene (100 parts) was added dropwisethereto at 170° C. for 3 hours to perform polymerization. The reactionmixture was kept at the same temperature for further 30 min. Next, theresultant mixture was desolvated to synthesize [graft polymer]. Theobtained [graft polymer] was found to have a Mw of 24,000 and a Tg of67° C.

—Preparation of Releasing Agent Dispersion Liquid (1)—

A container to which a stirring rod and a thermometer had been set wascharged with 50 parts of paraffin wax (product of NIPPON SEIRO CO. LTD.,HNP-9, hydrocarbon wax, melting point: 75° C., SP value: 8.8), 30 partsof the [graft polymer] and 420 parts of ethyl acetate, and the resultantmixture was increased in temperature to 80° C. under stirring, kept at80° C. for 5 hours and cooled to 30° C. for 1 hour. The paraffin wax wasdispersed in the resultant mixture using a beads mill (ULTRAVISCOMILL,product of Aimex CO. LTD.) under the following conditions:liquid-feeding rate: 1 kg/hr; disc-circumference speed: 6 m/sec; volumeof 0.5-mm zirconia beads packed: 80% by volume; and pass time: 3,whereby [releasing agent dispersion liquid (1)] was obtained.

—Preparation of Masterbatches (1) to (14)—

-   -   Crystalline polyurethane resin A-1: 100 parts    -   Carbon black (PRINTEX35, product of EVONIK DEGUSSA Co.): 100        parts    -   (DBP absorption amount: 42 mL/100 g, pH: 9.5)    -   Ion exchange water: 50 parts

The above-listed materials were mixed together using HENSCHEL MIXER(product of NIPPON COKE & ENGINEERING CO. LTD.). The resultant mixturewas kneaded using a two-roll. The kneading was initiated at atemperature of 90° C. and then the kneading temperature was graduallydecreased to 50° C. The obtained kneaded product was pulverized with apulverizer (product of Hosokawa Micron CO. LTD.) to prepare [masterbatch(1)].

The above procedure for preparing the [masterbatch (1)] was repeated,except that the binder resin used was changed from the crystallinepolyurethane resin A-1 to each binder resin described in Table 5, tothereby prepare [masterbatch (2)] to [masterbatch (14)].

TABLE 5 Binder resin Masterbatch (1) A-1 Masterbatch (2) A-2 Masterbatch(3) A-3 Masterbatch (4) A-4 Masterbatch (5) A-5 Masterbatch (6) A-6Masterbatch (7) A-7 Masterbatch (8) A-8 Masterbatch (9) A-9 Masterbatch(10)  A-10 Masterbatch (11)  A-11 Masterbatch (12)  A-12 Masterbatch(13)  A-13 Masterbatch (14) C-1—Preparation of Oil Phases (1) to (3), (5), (7) to (10), (14) to (17)and (21)—

A container equipped with a thermometer and a stirrer was charged with31.5 parts of the [urethane-modified crystalline polyester resin A-2]and ethyl acetate in such an amount that the solid content concentrationwould be 50% by mass, and the resultant mixture was heated to atemperature equal to or higher than the melting point of the resin forthorough dissolution. To the resultant solution were added 100 parts ofthe 50% by mass ethyl acetate solution of the [non-crystalline resinC-1], 60 parts of the [releasing agent dispersion liquid (1)] and 12parts of the [masterbatch (2)], and the resultant mixture was stirred at50° C. using a TK homomixer (product of PRIMIX CO. LTD.) at 5,000 rpm,so that the components were homogeneously dissolved or dispersed tothereby obtain [oil phase (1′)]. Notably, the temperature of the [oilphase (1′)] was kept at 50° C. in the container, and the [oil phase(1′)] was used within 5 hours after the preparation thereof so as not tobe crystallized.

Next, immediately before the below-described production of toner baseparticles, 25 parts of the ethyl acetate solution of [crystalline resinprecursor B′-5] was added to 235 parts of the [oil phase (1′)] kept at50° C., and the resultant mixture was stirred using a TK homomixer(product of PRIMIX CO. LTD.) at 5,000 rpm, so that the components werehomogenuously dissolved or dispersed to thereby prepare [oil phase (1)].

Oil phases (2), (3), (5), (7) to (10), (14) to (17) and (21) each wereprepared in the same manner as in the preparation of the oil phase (1)except that the type and amount of the crystalline resin A, the type andamount of the crystalline resin B, the type and amount of thenon-crystalline resin C, and the type of the masterbatch were changed asdescribed in Table 6. Notably, the [crystalline resin precursor B′-5]and the [non-crystalline resin precursor C-2] in Table 6 were addedimmediately before the production of toner base particles to prepareeach oil phase, similar to the case of the [crystalline resin precursorB′-5] in the preparation of the [oil phase (1)].

TABLE 6 Binder resin Crystalline Crystalline resin (A) resin (B)Non-crystalline resin (C) Masterbatch Oil Phase (1) A-2 31.5 B′-5 12.5C-1 50 — — (2) Oil Phase (2) A-2 46.5 B′-5 17.5 C-1 30 — — (2) Oil Phase(3) A-2 69 B′-5 25 — — — — (2) Oil Phase (5) A-2 50 B′-5 24 C-1 20 — —(2) Oil Phase (7) A-4 54 B′-5 20 C-1 20 — — (4) Oil Phase (8) A-5 54B′-5 20 C-1 20 — — (5) Oil Phase (9) A-7 54 B′-5 20 C-1 20 — — (7) OilPhase (10) A-8 54 B′-5 20 C-1 20 — — (8) Oil Phase (14) A-1 54 B′-5 20C-1 20 — — (1) Oil Phase (15) A-12 54 B′-5 20 C-1 20 — — (12) Oil Phase(16) A-13 54 B′-5 20 C-1 20 — — (13) Oil Phase (17) A-2 54 B′-5 20 C-120 — — (2) Oil Phase (21) A-2 15 — — C-1 62 C-2 17 (14)—Preparation of Aqueous Dispersion Liquid of Fine Resin Particles—

A reaction container to which a stirring rod and a thermometer had beenset was charged with 600 parts of water, 120 parts of styrene, 100 partsof methacrylic acid, 45 parts of butyl acrylate, 10 parts of sodiumalkylally sulfosuccinate (“ELEMINOL JS-2,” product of Sanyo ChemicalIndustries Ltd.) and 1 part of ammonium persulfate, and the resultantmixture was stirred at 400 rpm for 20 min to obtain white emulsion. Theobtained white emulsion was heated to 75° C. (system temperature) andallowed to react for 6 hours. In addition, 30 parts of a 1% by massaqueous ammonium persulfate solution was added to the reaction mixture,which was then aged at 75° C. for 6 hours, to thereby obtain [aqueousdispersion liquid of fine resin particles]. The particles contained inthe [aqueous dispersion liquid of fine resin particles] were found tohave a volume average particle diameter of 80 nm, and the resin thereofwas found to have a weight average molecular weight of 160,000 and a Tgof 74° C.

—Preparation of Aqueous Phase (1)—

Water (990 parts), 83 parts of the [aqueous dispersion liquid of fineresin particles], 37 parts of 48.5% by mass aqueous solution of sodiumdodecyl diphenyl ether disulfonate (“ELEMINOL MON-7,” product of SanyoChemical Industries Ltd.) and 90 parts of ethyl acetate were mixedtogether to obtain [aqueous phase (1)].

—Production of Toner Base Particles (1) to (3), (5), (7) to (10), (14)to (17) and (21)—

The [aqueous phase (1)] (520 parts) was added to another container towhich a stirrer and a thermometer had been set, and then heated to 40°C. While the [aqueous phase (1)] kept at 40° C. to 50° C. was beingstirred at 13,000 rpm using a TK homomixer (product of product of PRIMIXCO. LTD.), the [oil phase (1)] was added to the [aqueous phase (1)],followed by emulsification for 1 min, to thereby obtain [emulsifiedslurry 1].

Next, the obtained [emulsified slurry 1] was added to a container towhich a stirrer and a thermometer had been set, and then was desolvatedat 60° C. for 6 hours to thereby obtain [slurry 1]. The obtained [slurry1] was filtrated under reduced pressure and subjected to the followingwashing treatments.

(1) Ion exchange water (100 parts) was added to the filtration cake,followed by mixing with a TK homomixer (at 6,000 rpm for 5 min) andfiltrating.

(2) A 10% by mass aqueous sodium hydroxide solution (100 parts) wasadded to the filtration cake obtained in (1), followed by mixing with aTK homomixer (at 6,000 rpm for 10 min) and filtrating under reducedpressure.

(3) 10% by mass hydrochloric acid (100 parts) was added to thefiltration cake obtained in (2), followed by mixing with a TK homomixer(at 6,000 rpm for 5 min) and filtrating.

(4) Ion-exchange water (300 parts) was added to the filtration cakeobtained in (3), followed by mixing with a TK homomixer (at 6,000 rpmfor 5 min) and filtrating. This treatment was performed twice to therebyobtain filtration cake (1).

The obtained filtration cake (1) was dried with an air-circulation dryerat 45° C. for 48 hours, and then sieved with a mesh having an openingsize of 75 μm to obtain toner base particles (1).

In the same manner, toner base particles (2), (3), (5), (7) to (10),(14) to (17) and (21) were produced using the oil phases (2), (3), (5),(7) to (10), (14) to (17) and (21), respectively.

—Preparation of Oil Phases (4), (13) and (18) to (20)—

A container equipped with a thermometer and a stirrer was charged with62 parts of the [urethane-modified crystalline polyester resin A-2], 12parts of the [urethane-modified crystalline polyester resin B-2] andethyl acetate in such an amount that the solid content concentrationwould be 50% by mass, and the resultant mixture was heated to atemperature equal to or higher than the melting point of the resin forthorough dissolution. To the resultant solution were added 40 parts ofthe 50% by mass ethyl acetate solution of the [non-crystalline resinC-1], 60 parts of the [releasing agent dispersion liquid] and 12 partsof the [masterbatch (2)], and the resultant mixture was stirred at 50°C. using a TK homomixer (product of PRIMIX CO. LTD.) at 5,000 rpm, sothat the components were homogeneously dissolved or dispersed to therebyobtain [oil phase (4)]. Notably, the temperature of the [oil phase (4)]was kept at 50° C. in the container, and the [oil phase (4)] was usedwithin 5 hours after the preparation thereof so as not to becrystallized.

Oil phases (13) and (18) to (20) each were prepared in the same manneras in the preparation of the oil phase (4) except that the type andamount of the crystalline resin A, the type and amount of thecrystalline resin B, the type and amount of the non-crystalline resin C,and the type of the masterbatch were changed as described in Table 7.Notably, when the crystalline resin [B-1], [B-2], [B-3] or [B-4] wasused as Crystalline resin B in Table 7, the crystalline resin [B-1],[B-2], [B-3] or [B-4] was dissolved or dispersed together with othertoner materials at the oil phase preparation step.

TABLE 7 Binder resin Non- Crystalline Crystalline crystalline resin (A)resin (B) resin (C) Masterbatch Oil Phase (4) A-2 62 B-2 12 C-1 20 (2)Oil Phase (13) A-9 54 B-3 20 C-1 20 (9) Oil Phase (18) A-10 54 B-4 20C-1 20 (10) Oil Phase (19) A-11 54 B-1 20 C-1 20 (11) Oil Phase (20) A-274 — — C-1 20 (2)—Preparation of Aqueous Phase (2)—

Water (990 parts), 37 parts of 48.5% by mass aqueous solution of sodiumdodecyl diphenyl ether disulfonate (“ELEMINOL MON-7,” product of SanyoChemical Industries Ltd.) and 90 parts of ethyl acetate were mixedtogether to obtain [aqueous phase (2)].

—Production of Toner Base Particles (4), (13) and (18) to (20)—

The [aqueous phase (2)] (520 parts) was added to another container towhich a stirrer and a thermometer had been set, and then heated to 40°C. While the [aqueous phase (2)] kept at 40° C. to 50° C. was beingstirred at 13,000 rpm using a TK homomixer (product of product of PRIMIXCO. LTD.), the [oil phase (4)] was added to the [aqueous phase (2)],followed by emulsification for 1 min, to thereby obtain [emulsifiedslurry 4].

Next, the obtained [emulsified slurry 4] was added to a container towhich a stirrer and a thermometer had been set, and then was desolvatedat 60° C. for 6 hours to thereby obtain [slurry 4]. The obtained [slurry4] was filtrated under reduced pressure and subjected to the followingwashing treatments.

(1) Ion exchange water (100 parts) was added to the filtration cake,followed by mixing with a TK homomixer (at 6,000 rpm for 5 min) andfiltrating.

(2) A 10% by mass aqueous sodium hydroxide solution (100 parts) wasadded to the filtration cake obtained in (1), followed by mixing with aTK homomixer (at 6,000 rpm for 10 min) and filtrating under reducedpressure.

(3) 10% by mass hydrochloric acid (100 parts) was added to thefiltration cake obtained in (2), followed by mixing with a TK homomixer(at 6,000 rpm for 5 min) and filtrating.

(4) Ion-exchange water (300 parts) was added to the filtration cakeobtained in (3), followed by mixing with a TK homomixer (at 6,000 rpmfor 5 min) and filtrating. This treatment was performed twice to therebyobtain filtration cake (4).

The obtained filtration cake (4) was dried with an air-circulation dryerat 45° C. for 48 hours, and then sieved with a mesh having an openingsize of 75 μm to obtain toner base particles (4).

In the same manner, toner base particles (13) and (18) to (20) wereproduced using the oil phases (13) and (18) to (20), respectively.

—Preparation of Crystalline Resin Particle Dispersion Liquid (A-3)—

Ethyl acetate (60 parts) was added to 60 parts of the [urethane-modifiedcrystalline polyester resin A-3] and the resultant mixture was mixed andstirred at 50° C., so that the resin was dissolved to obtain a resinsolution. Separately, 120 parts of water, 6 parts of 48.3% by massaqueous solution of sodium dodecyl diphenyl ether disulfonate (“ELEMINOLMON-7,” product of Sanyo Chemical Industries Ltd.) and 2.4 parts of a 2%by mass aqueous sodium hydroxide solution were mixed together to prepare[aqueous phase]. Then, 120 parts of the above-obtained resin solutionwas added to the [aqueous phase] and the resultant mixture wasemulsified using a homogenizer (product of IKA Co., ULTRA-TURRAX T50).Thereafter, the emulsified mixture was subjected to emulsifyingtreatment using a MANTON-GAULIN high-pressure homogenizer (product ofGAULIN Co.) to thereby obtain [emulsified slurry A-3].

Next, a container to which a stirrer and a thermometer had been set wascharged with the [emulsified slurry A-3] and then desolvated at 60° C.for 4 hours, to thereby obtain [crystalline resin particle dispersionliquid (A-3)]. The particles contained in the obtained [crystallineresin particle dispersion liquid (A-3)] were measured using a particlesize distribution analyzer (LA-920, product of HORIBA CO. LTD.) forvolume average particle diameter, which was found to be 0.15 μm.

—Preparation of Crystalline Resin Particle Dispersion Liquid (A-6)—

Ethyl acetate (60 parts) was added to 60 parts of the [urethane-modifiedcrystalline polyester resin A-6] and the resultant mixture was mixed andstirred at 50° C., so that the resin was dissolved to obtain a resinsolution. Separately, 120 parts of water, 6 parts of 48.3% by massaqueous solution of sodium dodecyl diphenyl ether disulfonate (“ELEMINOLMON-7,” product of Sanyo Chemical Industries Ltd.) and 2.4 parts of a 2%by mass aqueous sodium hydroxide solution were mixed together to prepare[aqueous phase]. Then, 120 parts of the above-obtained resin solutionwas added to the [aqueous phase] and the resultant mixture wasemulsified using a homogenizer (product of IKA Co., ULTRA-TURRAX T50).Thereafter, the emulsified mixture was subjected to emulsifyingtreatment using a MANTON-GAULIN high-pressure homogenizer (product ofGAULIN Co.) to thereby obtain [emulsified slurry A-6].

Next, a container to which a stirrer and a thermometer had been set wascharged with the [emulsified slurry A-6] and then desolvated at 60° C.for 4 hours, to thereby obtain [crystalline resin particle dispersionliquid (A-6)]. The particles contained in the obtained [crystallineresin particle dispersion liquid (A-6)] were measured using a particlesize distribution analyzer (LA-920, product of HORIBA CO. LTD.) forvolume average particle diameter, which was found to be 0.18 μm.

—Preparation of Crystalline Resin Particle Dispersion Liquid (B-1)—

Ethyl acetate (60 parts) was added to 60 parts of the [urethane-modifiedcrystalline polyester resin B-1] and the resultant mixture was mixed andstirred at 50° C., so that the resin was dissolved to obtain a resinsolution. Separately, 120 parts of water, 6 parts of 48.3% by massaqueous solution of sodium dodecyl diphenyl ether disulfonate (“ELEMINOLMON-7,” product of Sanyo Chemical Industries Ltd.) and 2.4 parts of a 2%by mass aqueous sodium hydroxide solution were mixed together to prepare[aqueous phase]. Then, 120 parts of the above-obtained resin solutionwas added to the [aqueous phase] and the resultant mixture wasemulsified using a homogenizer (product of IKA Co., ULTRA-TURRAX T50).Thereafter, the emulsified mixture was subjected to emulsifyingtreatment using a MANTON-GAULIN high-pressure homogenizer (product ofGAULIN Co.) to thereby obtain [emulsified slurry B-1].

Next, a container to which a stirrer and a thermometer had been set wascharged with the [emulsified slurry B-1] and then desolvated at 60° C.for 4 hours, to thereby obtain [crystalline resin particle dispersionliquid (B-1)]. The particles contained in the obtained [crystallineresin particle dispersion liquid (B-1)] were measured using a particlesize distribution analyzer (LA-920, product of HORIBA CO. LTD.) forvolume average particle diameter, which was found to be 0.16 μm.

—Preparation of Non-Crystalline Resin Particle Dispersion Liquid (C-1)—

Ethyl acetate (60 parts) was added to 60 parts of the [non-crystallineresin C-1] and the resultant mixture was mixed and stirred, so that theresin was dissolved to obtain a resin solution. Separately, 120 parts ofwater, 6 parts of 48.3% by mass aqueous solution of sodium dodecyldiphenyl ether disulfonate (“ELEMINOL MON-7,” product of Sanyo ChemicalIndustries Ltd.) and 2.4 parts of a 2% by mass aqueous sodium hydroxidesolution were mixed together to prepare [aqueous phase]. Then, 120 partsof the above-obtained resin solution was added to the [aqueous phase]and the resultant mixture was emulsified using a homogenizer (product ofIKA Co., ULTRA-TURRAX T50). Thereafter, the emulsified mixture wassubjected to emulsifying treatment using a MANTON-GAULIN high-pressurehomogenizer (product of GAULIN Co.) to thereby obtain [emulsified slurryC-1].

Next, a container to which a stirrer and a thermometer had been set wascharged with the [emulsified slurry C-1] and then desolvated at 60° C.for 4 hours, to thereby obtain [non-crystalline resin particledispersion liquid (C-1)]. The particles contained in the obtained[non-crystalline resin particle dispersion liquid (C-1)] were measuredusing a particle size distribution analyzer (LA-920, product of HORIBACO. LTD.) for volume average particle diameter, which was found to be0.15 μm.

—Preparation of Releasing Agent Dispersion Liquid (2)—

Paraffin wax (product of NIPPON SEIRO CO. LTD., HNP-9, melting point:75° C.) (25 parts), 5 parts of an anionic surfactant (“ELEMINOL MON-7,”product of Sanyo Chemical Industries Ltd.) and 200 parts of water weremixed together and the resultant mixture was melted at 95° C. Next, themelt liquid was emulsified using a homogenizer (product of IKA Co.,ULTRA-TURRAX T50). Thereafter, the emulsified mixture was subjected toemulsifying treatment using a MANTON-GAULIN high-pressure homogenizer(product of GAULIN Co.) to thereby obtain [releasing agent dispersionliquid (2)].

—Preparation of Colorant Dispersion Liquid—

Carbon black (PRINTEX35, product of EVONIK DEGUSSA Co.) (20 parts), 2parts of an anionic surfactant (“ELEMINOL MON-7,” product of SanyoChemical Industries Ltd.) and 80 parts of water were mixed together andthe carbon black was dispersed using a TK homomixer (product of PRIMIXCO. LTD.) to thereby obtain [colorant dispersion liquid].

—Production of Toner Base Particles (6)—

The [crystalline resin particle dispersion liquid (A-3)] (190 parts), 63parts of the [crystalline resin particle dispersion liquid (B-1)], 63parts of the [non-crystalline resin particle dispersion liquid (C-1)],46 parts of the [releasing agent dispersion liquid (2)], 17 parts of the[colorant dispersion liquid] and 600 parts of water were mixed together,and the pH of the resultant mixture was adjusted to 10 with a 2% by massaqueous sodium hydroxide solution. Next, the mixture was heated to 60°C. while 50 parts of a 10% by mass aqueous magnesium chloride solutionwas being gradually added dropwise to the mixture under stirring. Themixture was kept at 60° C. until the volume average particle diameter ofthe aggregated particles became 5.3 μm, to thereby obtain [slurry 6].The obtained [slurry 6] was filtrated under reduced pressure and thensubjected to the above washing treatments (1) to (4), whereby filtrationcake (6) was obtained. The obtained filtration cake (6) was dried withan air-circulation dryer at 45° C. for 48 hours, and then sieved with amesh having an opening size of 75 μm to obtain toner base particles (6).

—Production of Toner Base Particles (11)—

The [crystalline resin particle dispersion liquid (A-6)] (190 parts), 63parts of the [crystalline resin particle dispersion liquid (B-1)], 63parts of the [non-crystalline resin particle dispersion liquid (C-1)],46 parts of the [releasing agent dispersion liquid (2)], 17 parts of the[colorant dispersion liquid] and 600 parts of water were mixed together,and the pH of the resultant mixture was adjusted to 10 with a 2% by massaqueous sodium hydroxide solution. Next, the mixture was heated to 60°C. while 50 parts of a 10% by mass aqueous magnesium chloride solutionwas being gradually added dropwise to the mixture under stirring. Themixture was kept at 60° C. until the volume average particle diameter ofthe aggregated particles became 5.9 μm, to thereby obtain [slurry 11].The obtained [slurry 11] was filtrated under reduced pressure and thensubjected to the above washing treatments (1) to (4), whereby filtrationcake (11) was obtained. The obtained filtration cake (11) was dried withan air-circulation dryer at 45° C. for 48 hours, and then sieved with amesh having an opening size of 75 μm to obtain toner base particles(11).

—Production of Toner Base Particles (12)—

The [urethane-modified crystalline polyester resin A-2] (60 parts), 20parts of the [urethane-modified crystalline polyester resin B-1], 20parts of the [non-crystalline resin C-1], 5 parts of paraffin wax(product of NIPPON SEIRO CO. LTD., HNP-9, melting point: 75° C.) and 12parts of the [masterbatch (2)] were preliminarily mixed together usingHENSCHEL MIXER (product of NIPPON COKE & ENGINEERING CO. LTD., FM10B)and the resultant mixture was melted and kneaded using a biaxial kneader(product of IKEGAI Co. Ltd., PCM-30) at 80° C. to 120° C. The kneadedproduct was cooled to room temperature and then coarsely milled using ahammer mill so as to be 200 μm to 300 μm. Next, the milled product wasfinely milled using ultrasonic jet mill LABOJET (product of NipponPneumatic Mfg. Co. Ltd.) while the air pressure for the milling wasappropriately adjusted so that the finely milled product had a weightaverage particle diameter of 6.2 μm±0.3 μm. Thereafter, the obtainedparticles were classified using an air classifier (product of NipponPneumatic Mfg. Co. Ltd., MDS-I) while the space between the louvers wasappropriately adjusted so that the amount of fine particles havingdiameters less than 4 μm became 10% by number or less, whereby [tonerbase particles (12)] having a weight average particle diameter of 7.0μm±0.2 μm was obtained.

—Production of Toners (2-1) to (2-21)—

Using HENSCHEL MIXER (product of NIPPON COKE & ENGINEERING CO. LTD.),each (100 parts) of the obtained toner base particles (1) to (21) wasmixed with 1.0 part of hydrophobic silica (HDK-2000, product of WackerChemie AG) serving as an external additive at a circumferential speed of30 m/sec with five cycles each consisting of mixing for 30 sec andsuspending for 1 min. The resultant mixture was sieved with a meshhaving an opening size of 35 μm to produce toners (2-1) to (2-21).

As shown in Table 8-1, these toners are those of Examples 12 to 24,Referential Examples 1 to 4 and Comparative Examples 4 to 7.

A toner of Example 22-2 was produced in the same manner as in Example 22except that the conditions for the desolvation were changed from 60° C.for 6 hours to 70° C. for 3 hours.

A toner of Example 22-3 was produced in the same manner as in Example 22except that the conditions for the desolvation were changed to 40° C.for 10 hours.

A toner of Example 24-2 was produced in the same manner as in Example 24except that the conditions for the heating after production of tonerwere changed from 45° C. for 48 hours to 55° C. for 24 hours.

A toner of Example 24-3 was produced in the same manner as in Example 24except that the conditions for the heating after production of tonerwere changed to 35° C. for 96 hours.

The obtained toners (2-1) to (2-21) were each measured for particle sizedistribution (Dv, Dn, Dv/Dn), Tsh2nd/Th1st, storage elastic modulusG′(70), storage elastic modulus G′(160) and crystallinity. Thesecharacteristics were measured by the above-described methods. Themeasurement results are shown in Tables 8-1, 9-1 and 9-2.

<Production of Carrier>

-   -   Silicone resin (organostraight silicone): 100 parts    -   γ-(2-Aminoethyl)aminopropyltrimethoxysilane: 5 parts    -   Carbon black: 10 parts    -   Toluene: 100 parts

The above materials were dispersed using a homomixer for 20 min toprepare a resin layer-coating liquid. Thereafter, the surfaces ofspherical ferrite particles (1,000 parts) having a volume averageparticle diameter of 35 μm were coated with the resin layer-coatingliquid using a fluidized-bed coating apparatus, to thereby produce acarrier.

<Production of Developer>

Each (5 parts) of the toners (2-1) to (2-21) was mixed with 95 parts ofthe carrier to thereby produce developers of Examples 12 to 24 andComparative Examples 4 to 7.

Next, each of the produced developers was evaluated in the followingmanner for fixability (minimum fixing temperature and fixable range),heat resistance storage stability and stress resistance. The evaluationsfor these properties were considered as a whole. The evaluation resultsare shown in Table 9-2.

<<Fixability (Minimum Fixing Temperature)>>

Using a tandem full-color image forming apparatus 100C depicted in FIG.6, a solid image having an image size of 3 cm×8 cm was formed on a papersheet (product of Ricoh Business Expert, Ltd., a copy paper sheet <70>),the solid image having a toner deposition amount of 0.85±0.10 mg/cm².Then, the formed solid image was fixed with the temperature of thefixing belt changed. The fixed image surface was drawn with a rubyneedle (tip radius: 260 μmR to 320 μmR, tip angle: 60 degrees) at a loadof 50 g using draw tester AD-401 (product of Ueshima Seisakusho Co.,Ltd.). The drawn image surface was strongly rubbed five times with afabric (HONECOTTO #440, Hanylon Co. Ltd.). Here, the temperature of thefixing belt at which almost no peeling-off of the image occurred wasdetermined as the minimum fixing temperature. The solid image was formedon the paper sheet at a position 3.0 cm away from an edge of the papersheet that entered the image forming apparatus. Notably, the speed atwhich the paper sheet passed through the nip portion of the fixingdevice was 280 mm/s. The lower minimum fixing temperature means the moreexcellent low-temperature fixability.

[Evaluation Criteria]

A: Minimum fixing temperature≦105° C.

B: 105° C.<Minimum fixing temperature≦115° C.

C: 115° C.<Minimum fixing temperature≦130° C.

D: 130° C.<Minimum fixing temperature

<<Fixability (Hot Offset Resistance, Fixable Range)>>

Using a tandem full-color image forming apparatus 100C depicted in FIG.6, a solid image having an image size of 3 cm×8 cm was formed on a papersheet (product of Ricoh Company, Ltd., Type 6200), the solid imagehaving a toner deposition amount of 0.85±0.10 mg/cm². Then, the formedsolid image was fixed with the temperature of the fixing belt changed,to thereby visually evaluate whether or not hot offset occurred. Here,the fixable range is a difference between the minimum fixing temperatureand the maximum temperature at which no hot offset occurred. The solidimage was formed on the paper sheet at a position 3.0 cm away from anedge of the paper sheet that entered the image forming apparatus.Notably, the speed at which the paper sheet passed through the nipportion of the fixing device was 280 mm/s. The wider fixable range meansthe more excellent hot offset resistance. Conventional full-color tonershave a fixable range of about 50° C. on average.

[Evaluation Criteria]

A: 100° C.<Fixable range

B: 55° C.<Fixable range≦100° C.

C: 30° C.<Fixable range≦55° C.

D: Fixable range≦30° C.

<<Heat Resistance Storage Stability (Penetration Degree)>>

Each toner was charged into a 50-mL glass container and left to stand ina thermostat bath of 50° C. for 24 hours. The thus-treated toner wascooled to 24° C. and then measured for penetration degree (mm) by thepenetration degree test (JISK2235-1991) and evaluated according to thefollowing evaluation criteria. Notably, the greater penetration degreemeans the more excellent heat resistance storage stability. Toner havinga penetration degree of less than 5 mm is highly likely to involveproblems in use.

Notably, the penetration degree in the present invention is expressed bythe penetration depth (mm).

[Evaluation Criteria]

A: 25 mm≦Penetration degree

B: 15 mm≦Penetration degree<25 mm

C: 5 mm≦Penetration degree<15 mm

D: Penetration degree<5 mm

<<Stress Resistance>>

Using a tandem full-color image forming apparatus 100C depicted in FIG.6, a chart having an image occupation rate of 0.5% was formed on 50,000sheets. Thereafter, a solid image was formed on a sheet and the obtainedsheet was visually observed for whether the image portion had whitespots free of the toner and evaluated according to the followingevaluation criteria.

[Evaluation Criteria]

A: White spots free of the toner were not observed in the image portion;excellent state

B: Few white spots free of the toner were observed in the image portion;good state

C: Some white spots free of the toner were observed in the imageportion; but non-problematic in practical use

D: Numerous white spots free of the toner were observed in the imageportion; and problematic in practical use

<<Transferability>>

Using a tandem full-color image forming apparatus 100C depicted in FIG.6, a chart having an image occupation rate of 0.5% was formed on 50,000sheets. Thereafter, in the course of formation of a solid image on asheet, the image forming apparatus was stopped in operation immediatelyafter the image had been transferred from a photoconductor (10) to anintermediate transfer belt (50). The photoconductor was taken out andthen visually observed for untransfered toner remaining the transferportion thereof and evaluated according to the following evaluationcriteria. The evaluation results are shown in Table 9-2.

[Evaluation Criteria]

A: No untransferred toner was observed on the photoconductor; excellentstate

B: Untransferred toner was slightly observed on the photoconductor tosuch an extent that the color of the background of the photoconductorcould be perceived; good state

C: Untransferred toner was observed on the photoconductor and thebackground of the photoconductor was somewhat covered therewith; butnon-problematic in practical use

D: Much untransferred toner was observed on the photoconductor and thebackground of the photoconductor was almost covered therewith; andproblematic in practical use

TABLE 8-1 Characteristics of toners Presence Ratio of or absence DSCpeak Storage binder Dv of urea bond temperature Tsh2nd/ modulus G′[Pa]Toner No. resin [μm] detected (° C.) Tsh1st G′(70) G′(160) (C)/((C) +(A)) Ex. 12 Toner (2-1) 50 6.0 Presence 55.6 0.85 1.0E+06 2.0E+03 0.15Ex. 13 Toner (2-2) 70 5.7 Presence 56.6 0.90 2.0E+05 6.0E+03 0.21 Ex. 14Toner (2-3) 100 5.9 Presence 60.7 1.05 4.0E+04 9.0E+03 0.31 Ref. Ex. 1Toner (2-4) 80 6.0 Absence 59.2 0.95 9.0E+04 9.5E+02 0.28 Ex. 15 Toner(2-5) 80 5.7 Presence 57.4 0.90 1.0E+05 1.1E+04 0.21 Ref. Ex. 2 Toner(2.6) 80 5.3 Absence 58.0 0.95 4.0E+04 4.0E+03 0.25 Ex. 16 Toner (2-7)80 5.4 Presence 59.4 0.95 4.0E+05 6.0E+03 0.25 Ex. 17 Toner (2-8) 80 5.6Presence 51.8 0.95 4.5E+04 5.0E+03 0.25 Ex. 18 Toner (2-9) 80 5.8Presence 62.3 0.95 2.0E+05 6.0E+03 0.25 Ex. 19 Toner (2-10) 80 6.0Presence 59.1 0.95 3.0E+04 5.0E+03 0.26 Ref. Ex. 3 Toner (2-11) 80 5.9Absence 55.5 0.95 6.0E+05 7.0E+03 0.24 Ref. Ex. 4 Toner (2-12) 80 6.8Absence 60.8 0.95 3.0E+04 1.5E+03 0.27 Ex. 20 Toner (2-13) 80 6.3Presence 62.6 0.85 6.0E+05 9.0E+02 0.13 Ex. 21 Toner (2-14) 80 5.6Presence 57.2 0.85 5.9E+05 1.5E+04 0.14 Ex. 22 Toner (2-15) 80 6.2Presence 57.7 0.90 6.0E+04 5.0E+03 0.22 Ex. 23 Toner (2-16) 80 5.4Presence 57.9 0.85 5.5E+05 7.0E+03 0.18 Ex. 24 Toner (2-17) 80 5.2Presence 57.7 0.95 6.0E+04 4.0E+03 0.23 Comp. Ex. 4 Toner (2-18) 80 5.9Absence 56.5 1.05 1.0E+04 8.0E+02 0.39 Comp. Ex. 5 Toner (2-19) 80 5.3Absence 60.9 1.05 3.0E+04 2.0E+03 0.37 Comp. Ex. 6 Toner (2-20) 80 6.2Absence 59.1 0.95 9.0E+04 1.0E+02 0.24 Comp. Ex. 7 Toner (2.21) 15 6.3Absence 55.8 0.30 4.0E+06 5.0E+03 0.01

TABLE 8-2 THF/Ac OEt insoluble Physical properties N (C)/ content ΔH100,000 250,000 (% by ((C) + (% by ΔH ΔH (H)/ Mn Mw Mpt or more or moreMw/Mn mass) Urethane Urea (A)) mass) (T) (H) ΔH(T) Ex. 12 8,400 22,70021,300 13.3 1.2 2.70 0.43 Presence Presence 0.15 13.9 30.6 38.5 1.26 Ex.13 9,300 27,800 25,000 14.8 1.5 2.99 0.62 Presence Presence 0.21 15.242.2 48.5 1.15 Ex. 14 13,800 40,000 36,400 21.1 1.9 2.90 0.90 PresencePresence 0.31 18.1 70.4 69.5 0.99 Ref. Ex. 1 7,600 21,200 19,500 3.1 0.22.79 0.58 Presence Absence 0.28 9.8 50.9 37.0 0.73 Ex. 15 12,600 33,90031,500 19.7 1.7 2.69 0.73 Presence Presence 0.21 17.7 48.2 50.2 1.04Ref. Ex. 2 7,200 21,700 20,400 2.4 0.1 3.01 2.21 Presence Absence 0.259.3 51.4 36.0 0.70 Ex. 16 14,700 42,500 38,300 16.3 1.4 2.89 0.62Presence Presence 0.25 15.4 50.9 52.2 1.03 Ex. 17 10,200 28,600 26,00017.5 1.7 2.80 0.84 Presence Presence 0.25 16.8 50.6 53.1 1.05 Ex. 1814,400 38,800 35,700 18.6 1.6 2.69 0.73 Presence Presence 0.25 17.2 50.951.9 1.02 Ex. 19 8,400 25,300 23,500 16.8 1.6 3.01 0.78 PresencePresence 0.26 15.8 51.3 54.9 1.07 Ref. Ex. 3 13,300 38,700 36,400 5.20.4 2.91 1.25 Presence Absence 0.24 11.4 50.9 41.0 0.81 Ref. Ex. 4 9,10025,500 23,000 3.9 0.3 2.80 0.60 Presence Absence 0.27 10.5 50.7 38.00.75 Ex. 20 10,300 27,900 25,400 17.2 1.7 2.71 8.99 Presence Presence0.13 16 45.6 37.0 0.81 Ex. 21 10,300 30,900 28,400 18.4 1.7 3.00 4.53Presence Presence 0.14 16.9 46.3 36.0 0.78 Ex. 22 11,400 33,100 30,80016.5 1.7 2.90 1.93 Presence Presence 0.22 14.5 48.2 53.8 1.12 Ex. 2312,200 34,100 32,100 17.7 1.6 2.80 2.45 Presence Presence 0.18 17.1 45.654.2 1.19 Ex. 24 12,000 32,300 29,100 15.8 1.6 2.69 0.71 PresencePresence 0.23 12.2 50.9 54.1 1.06 Comp. Ex. 4 5,600 16,900 15,400 1.10.1 3.02 0.00 Absence Absence 0.39 8.4 55.7 39.7 0.71 Comp. Ex. 5 11,00032,000 29,400 2.1 0.2 2.91 0.10 Presence Absence 0.37 8.9 56.3 40.1 0.71Comp. Ex. 6 6,800 19,000 17,700 1.6 0.1 2.79 0.62 Presence Absence 0.247.8 50.9 44.2 0.87 Comp. Ex. 7 3,600 9,600 9,000 15.4 1.5 2.67 0.13Presence Absence 0.01 9.7 9.0 4.2 0.47

TABLE 8-3 Evaluation for fixation Post-fixation Fixability stateGlossiness 55T 135T 55T 135T 55T 135T Difference Ex. 12 B B C C 13.010.5 2.5 Ex. 13 B B B C 10.2 8.3 1.9 Ex. 14 A A A A 2.2 1.8 0.4 Ref. Ex.1 D C C C 27.5 18.8 8.7 Ex. 15 B A B B 8.1 6.6 1.5 Ref. Ex. 2 D C C C26.2 15.8 10.4 Ex. 16 A A A A 9.8 7.9 1.9 Ex. 17 B B C C 7.4 6.0 1.4 Ex.18 B A A B 5.1 4.1 1.0 Ex. 19 B B B C 12.6 10.2 2.4 Ref. Ex. 3 C C A B24.3 16.6 7.7 Ref. Ex. 4 D C B B 24.7 14.5 10.2 Ex. 20 B B B C 8.9 7.21.7 Ex. 21 B A B B 6.5 5.3 1.2 Ex. 22 B A B B 7.5 6.1 1.4 Ex. 23 B A B B11.7 9.5 2.2 Ex. 24 B A B B 12.7 10.3 2.4 Comp. Ex. 4 D D — — — — —Comp. Ex. 5 D C — A — 19.3 — Comp. Ex. 6 D D — — — — — Comp. Ex. 7 D D —— — — —

TABLE 9-1 Ratio of Storage modulus crystalline G′[Pa] resin Dv [μm] Dn[μm] Dv/Dn Tsh2nd/Tsh1st G′(70) G′(160) Ex. 12 Toner (2-1) 50 6.0 5.21.15 0.85 1.00E+06 2.00E+03 Ex. 13 Toner (2-2) 70 5.7 5.0 1.14 0.902.00E+05 6.00E+03 Ex. 14 Toner (2-3) 100 5.9 5.1 1.16 1.05 4.00E+049.00E+03 Ref. Ex. 1 Toner (2-4) 80 6.0 4.6 1.30 0.95 9.00E+04 9.50E+02Ex. 15 Toner (2.5) 80 5.7 5.0 1.14 0.9 1.00E+05 1.10E+04 Ref. Ex. 2Toner (2-6) 80 5.3 4.5 1.18 0.95 4.00E+04 4.00E+03 Ex. 16 Toner (2-7) 805.4 4.6 1.17 0.95 4.00E+05 6.00E+03 Ex. 17 Toner (2-8) 80 5.6 4.8 1.170.95 4.50E+04 5.00E+03 Ex. 18 Toner (2-9) 80 5.8 5.1 1.14 0.95 2.00E+056.00E+03 Ex. 19 Toner (2-10) 80 6.0 5.2 1.15 0.95 3.00E+04 5.00E+03 Ref.Ex. 3 Toner (2-11) 80 5.9 5.1 1.16 0.95 6.00E+05 7.00E+03 Ref. Ex. 4Toner (2-12) 80 6.8 5.5 1.24 0.95 3.00E+04 1.50E+03 Ex. 20 Toner (2-13)80 6.3 4.8 1.31 0.85 6.00E+05 9.00E+02 Ex. 21 Toner (2.14) 80 5.6 4.81.17 0.85 5.90E+05 1.50E+04 Ex. 22 Toner (2-15) 80 6.2 5.4 1.15 0.906.00E+04 5.00E+03 Ex. 22-2 Toner (2-15-2) 80 6.3 5.3 1.19 0.9 5.80E+044.90E+03 Ex. 22-3 Toner (2-15-3) 80 6.1 5.4 1.13 0.92 6.20E+04 5.10E+03Ex. 23 Toner (2.16) 80 5.4 4.7 1.15 0.85 5.50E+05 7.00E+03 Ex. 24 Toner(2-17) 80 5.2 4.6 1.13 0.95 6.00E+04 4.00E+03 Ex. 24-2 Toner (17-2) 805.3 4.6 1.15 0.93 5.70E+04 3.50E+03 Ex. 24-3 Toner (17-3) 80 5.2 4.71.11 0.98 6.40E+04 4.50E+03 Comp. Ex. 4 Toner (2-18) 80 5.9 4.4 1.341.05 1.00E+04 8.00E+02 Comp. Ex. 5 Toner (2-19) 80 5.3 4.0 1.33 1.053.00E+04 2.00E+03 Comp. Ex. 6 Toner (2.20) 80 6.2 4.8 1.29 0.95 9.00E+041.00E+02 Comp. Ex. 7 Toner (2-21) 15 6.3 4.8 1.31 0.30 4.00E+06 5.00E+03

TABLE 9-2 Crystallinity Resistivity Fixability Heat-resistant [%] logRMin. fixing temp. Fixable range storage stability Stress resistanceTransferability Ex. 12 15 10.1 125 55 C A C Ex. 13 21 10.3 105 >100 A AB Ex. 14 31 10.7 105 >100 A C A Ref. Ex. 1 28 10.3 105 40 A B B Ex. 1521 10.2 115 >100 A B B Ref. Ex. 2 25 10.3 105 70 C A B Ex. 16 25 9.9110 >100 A A C Ex. 17 25 10.3 105 >100 B A B Ex. 18 25 10.1 105 >100 A AC Ex. 19 26 10.3 100 >100 C C B Ref. Ex. 3 24 10.4 115 70 A A A Ref. Ex.4 27 10.5 110 70 B B A Ex. 20 13 10.1 115 70 C A C Ex. 21 14 10 115 >100C A C Ex. 22 22 10.3 105 >100 A A B Ex. 22-2 18 9.9 110 >100 B B C Ex.22-3 27 10.6 100 >100 A A A Ex. 23 18 10.2 115 >100 B A B Ex. 24 23 10.4105 >100 A A B Ex. 24-2 15 9.9 105 >100 B B C Ex. 24-3 29 10.6 100 >100A A A Comp. Ex. 4 39 10.8 105 40 C D B Comp. Ex. 5 37 10.7 105 65 B D BComp. Ex. 6 24 9.8 110 20 B C D Comp. Ex. 7 — 10.9 140 55 B A B

As shown in Tables 8-3 and 9-2, the developers of Examples 12 to 24 weresuperior to those of Comparative Examples 4 to 7 in low-temperaturefixability, fixable range, heat resistance storage stability and stressresistance.

Embodiments of the present invention are as follows.

<1> A toner, including:

a crystalline resin as a binder resin,

wherein a tetrahydrofuran soluble content of the toner includes 5.0% ormore as a peak area of a component having a molecular weight of 100,000or greater in a molecular weight distribution measured by gel permeationchromatography, and

wherein the tetrahydrofuran soluble content of the toner has aweight-average molecular weight of 20,000 to 60,000.

<2> The toner according to <1>, wherein, in a diffraction spectrum ofthe toner obtained by an x-ray diffraction apparatus, a ratio of (C)integrated intensity of a spectrum derived from a crystalline structureto a sum of the (C) and (A) integrated intensity of a spectrum derivedfrom a non-crystalline structure [C/(A+C)] is 0.13 or greater.

<3> The toner according to any one of <1> and <2>, wherein thetetrahydrofuran soluble content of the toner includes 0.5% or more as apeak area of a component having a molecular weight of 250,000 or greaterin the molecular weight distribution measured by gel permeationchromatography.

<4> The toner according to any one of <1> to <3>, wherein a ratio[ΔH(H)/ΔH(T)] of an endothermic quantity [ΔH(T), (J/g)] in adifferential scanning calorimetry of the toner and an endothermicquantity [ΔH(H), (J/g)] in a differential scanning calorimetry of aninsoluble content of the toner with respect to a mixed solvent oftetrahydrofuran and ethyl acetate [tetrahydrofuran/ethyl acetate=50/50(mass ratio)] is 0.20 to 1.25.

<5> The toner according to any one of <1> to <4>, wherein thecrystalline resin includes a crystalline resin including a urethane bondor a urea bond or both thereof.

<6> The toner according to <5>, wherein the crystalline resin includinga urethane bond or a urea bond or both thereof includes a componentwhere a modified crystalline resin having an isocyanate group at an endthereof is elongated.

<7> The toner according to any one of <5> and <6>, wherein thecrystalline resin including a urethane bond or a urea bond or boththereof includes a first crystalline resin and a second crystallineresin having a weight-average molecular weight greater than that of thefirst crystalline resin.

<8> The toner according to any one of <5> to <7>, wherein thecrystalline resin including a urethane bond or a urea bond or boththereof includes a crystalline resin including a polyurethane unit and acrystalline polyester unit.

<9> The toner according to any one of <5> to <8>, wherein a content of Nelement in a CHN analysis of the tetrahydrofuran soluble content of thetoner is 0.3% by mass to 2.0% by mass.

<10> The toner according to any one of <1> to <9>, wherein an insolublecontent of the toner with respect to a mixed solution of tetrahydrofuranand ethyl acetate (tetrahydrofuran/ethyl acetate=50/50 (mass ratio)) is10.0% by mass or greater.

<11> The toner according to any one of <1> to <10>, wherein a commonlogarithmic value of a volume resistivity R of the toner by an AC bridgemethod is 10.0 to 10.6.

<12> A developer, including:

the toner according to any one of <1> to <11>.

<13> An image forming apparatus, including:

an electrostatic latent image bearing member;

an electrostatic latent image forming unit which is configured to forman electrostatic latent image on the electrostatic latent image bearingmember; and

a developing unit which is configured to develop the electrostaticlatent image formed on the electrostatic latent image bearing member toform a visible image and which includes a toner,

wherein the toner is the toner according to any one of <1> to <11>.

REFERENCE SIGNS LIST

-   10: Photoconductor (photoconductor drum)-   61: Developing device-   100A: Image forming apparatus-   100B: Image forming apparatus-   100C: Image forming apparatus

The invention claimed is:
 1. A toner, comprising: a binder resincomprising a crystalline resin comprising a polyurethane urethane bond,a urea bond, or a combination thereof, wherein the crystalline resincomprising a urethane bond, a urea bond, or a combination thereofcomprises a crystalline resin comprising a polyurethane unit and acrystalline polyester unit, wherein a tetrahydrofuran soluble content ofthe toner comprises 5.0% or more as a peak area of a component having amolecular weight of 100,000 or greater in a molecular weightdistribution measured by gel permeation chromatography, and wherein thetetrahydrofuran soluble content of the toner has a weight-averagemolecular weight in the range of 20,000 to 60,000.
 2. The toner of claim1, wherein a ratio of (C) integrated intensity of a spectrum derivedfrom a crystalline structure to a sum of the (C) and (A) integratedintensity of a spectrum derived from a non-crystalline structure[C/(A+C)] is 0.13 or greater in a diffraction spectrum of the tonerobtained by an x-ray diffraction apparatus.
 3. The toner of claim 1,wherein the tetrahydrofuran soluble content of the toner comprises atleast 0.5% or more as a peak area of a component having a molecularweight of 250,000 or greater in the molecular weight distributionmeasured by gel permeation chromatography.
 4. The toner of claim 1,wherein a ratio [ΔH(H)/ΔH(T)] of an endothermic quantity [ΔH(T), (J/g)]in a differential scanning calorimetry of the toner and an endothermicquantity [ΔH(H), (J/g)] in a differential scanning calorimetry of aninsoluble content of the toner with respect to a mixed solvent oftetrahydrofuran and ethyl acetate [tetrahydrofuran/ethyl acetate=50/50(mass ratio)] is in the range of 0.20 to 1.25.
 5. The toner of claim 1,wherein the crystalline resin comprising a urethane bond, a urea bond,or a combination thereof comprises a component wherein a modifiedcrystalline resin having an isocyanate group at an end thereof iselongated.
 6. The toner of claim 1, wherein the crystalline resincomprising a urethane bond, a urea bond, or a combination thereofcomprises a first crystalline resin and a second crystalline resinhaving a weight-average molecular weight greater than that of the firstcrystalline resin.
 7. The toner of claim 1, wherein a content of Nelement in a CHN analysis of the tetrahydrofuran soluble content of thetoner is in the range of 0.3% by mass to 2.0% by mass.
 8. The toner ofclaim 1, wherein an insoluble content of the toner with respect to amixed solution of tetrahydrofuran and ethyl acetate(tetrahydrofuran/ethyl acetate=50/50 (mass ratio)) is 10.0% by mass orgreater.
 9. The toner of claim 1, wherein a common logarithmic value ofa volume resistivity R of the toner by an AC bridge method is in therange of 10.0 to 10.6.
 10. A developer, comprising: a toner comprising abinder resin comprising a crystalline resin comprising a polyurethaneurethane bond, a urea bond, or a combination thereof, wherein thecrystalline resin comprising a urethane bond, a urea bond, or acombination thereof comprises a crystalline resin comprising apolyurethane unit and a crystalline polyester unit, wherein atetrahydrofuran soluble content of the toner comprises 5.0% or more as apeak area of a component having a molecular weight of 100,000 or greaterin a molecular weight distribution measured by gel permeationchromatography, and wherein the tetrahydrofuran soluble content of thetoner has a weight-average molecular weight of 20,000 to 60,000.